大晟乐辨三题

北宋徽宗崇宁四年(1105)九月,朝廷以新乐修成,赐名《大晟》,特置府建官.     

A comprehensive review of hydrocarbons and genetic model of the sandstone‐hosted Dongsheng uranium deposit,Ordos Basin,China

The Dongsheng uranium deposit, the largest in situ leach uranium mine in the Ordos Basin, geometrically forms a roll‐front type deposit that is hosted in the Middle Jurassic Zhiluo Formation. The genesis of the mineralization, however, has long been a topic of great debate. Regional faults, epigenetic alterations in surface outcrops, natural oil seeps, and experimental findings support a reducing microenvironment during ore genesis. The bulk of the mineralization is coffinite. Based on thin‐section petrography, some of the coffinite is intimately intergrown with authigenic pyrite (ore‐stage pyrite) and is commonly juxtaposed with some late diagenetic sparry calcite (ore‐stage calcite) in primary pores, suggesting simultaneous precipitation. Measured homogenization temperatures of greater than 100°C from fluid inclusions indicate circulation of low‐temperature hydrothermal fluids in the ore zone. The carbon isotopic compositions of late calcite cement (δ¹³C_VPDB = ?31.0 to ?1.4‰) suggest that they were partly derived from sedimentary organic carbon, possibly from deep‐seated petroleum fluids emanating from nearby faults. Hydrogen and oxygen isotope data from kaolinite cement (δD = ?133 to ?116‰ and δ¹⁸O_SMOW = 12.6–13.8‰) indicate that the mineralizing fluids differed from magmatic and metamorphic fluids and were more depleted in D (²H) than modern regional meteoric waters. Such a strongly negative hydrogen isotopic signature suggests that there has been selective modification of δD by CH₄±H₂S±H₂ fluids. Ore‐stage pyrite lies within a very wide range of δ³⁴S (?39.2 to 26.9‰), suggesting that the pyrite has a complex origin and that bacterially mediated sulfate reduction cannot be precluded. Hydrocarbon migration and its role in uranium reduction and precipitation have here been unequivocally defined. Thus, a unifying model for uranium mineralization can be established: Early coupled bacterial uranium mineralization and hydrocarbon oxidation were followed by later recrystallization of ore phases in association with low‐temperature hydrothermal solutions under hydrocarbon‐induced reducing conditions.     

Bleached mudstone,iron concretions,and calcite veins: a natural analogue for the effects of reducing CO2‐bearing fluids on migration and mineralization of iron,sealing properties,and composition of mudstone cap rocks

This study investigates the Wangfu Depression of the Songliao Basin, China, as a natural analogue site for Fe migration (bleaching) and mineralization (formation of iron concretions) caused by reducing CO₂‐bearing fluids that leak along fractures after carbon capture, utilization, and storage. We also examined the origin of fracture‐filling calcite veins, the properties of self‐sealing fluids, the influence of fluids on the compositions of mudstone and established a bleaching model for the study area. Our results show that iron concretions are the oxidative products of precursor minerals (pyrite and siderite) during uplift and are linked to H₂S and CO₂ present in early stage fluids. The precipitation of calcite veins is the result of CO₂ degassing and is related to CO₂, CH₄, and minor heavy hydrocarbons in the main bleaching fluids. In our model, fluids preferentially enter high‐permeability fracture systems and result in the bleaching of surrounding rocks and precipitation of calcite veins. The infilling of calcite veins significantly decreases the permeability of fractures and forces the fluids to slowly enter and bleach the mudstone rocks. The Fe²⁺ released during bleaching migrates to elsewhere with the solutions or is reprecipitated in the calcite veins and iron concretions. The formation of calcite veins reduces the fracture space and effectively prevents fluid flow. The fluids have an insignificant effect on minerals within the mudstone. In terms of the chemistry of the mudstone, only the contents of Fe₂O₃, U, and Mo change significantly, with the content of U increasing in the mudstone and the contents of Fe₂O₃ and Mo decreasing during bleaching.     

Phytolith analysis for the identification of barnyard millet (<Emphasis Type="Italic">Echinochloa</Emphasis> sp.) and its implications

Echinochloa was an important prehistoric food crop of early agriculture in Asia. Macro-remains can be used to identify Echinochloa. However, when few macro-remains are available, phytolith analysis can be performed. In this study, we examined the phytolith morphology of the glumes, lemmas, and paleas from the inflorescence bracts of nine Echinochloa species from different regions of China and obtained diagnostic, morphological, and morphometric characteristics for Echinochloa. Phytoliths in Echinochloa are different from those in most known crops except those in Setaria italica and Panicum miliaceum. We found the following two diagnostic features within an epidermal silica layer that can be used to distinguish Echinochloa sp. from S. italica and P. miliaceum: (1) the β-type undulated patterns with constricted top of the undulation amplitude and (2) the discriminant functions based on the morphometric data of the β-type undulated patterns, which suggested that 94.9 % of the cross-validated data were correctly classified into Echinochloa, S. italica, and P. miliaceum. Thus, we established the phytolith identification criteria for Echinochloa; this could have important implications in plant taxonomy, archaeobotany, and plant domestication.     

高度重视和切实加强民族信息工作

高度重视和切实加强民族信息工作,是做好新世纪民族工作的需要。随着民族工作的不断深入,民族信息工作对于促进民族工作的作用愈将显示出来,本详细论述了新时期民族信息工作的任务、内容、基本原则;对如何做好新时期民族信息工作也提出了几点建议。     

战国魏大梁城平面布局新探

战国魏大梁城位于今开封市城区偏北部,其平面布局一直没有定论,本文综合考古钻探成果、历史文献并结合开封历史地理的实际情况,首次绘制了大梁城平面布局示意图。大梁城平面大致呈不规则的长方形,有郭城和宫城两部分组成,宫城位于郭城东南部。浚仪渠从郭城北部自西向东穿城而过。宫殿区位于宫城西部正中的高台区域,手工业区位于郭城北部的浚仪渠两侧。     

唐代宫廷女性画像与外来艺术手法——以新见唐武惠妃石椁女性线刻画为典型

本文针对盛唐贞顺皇后(武惠妃)石椁内壁十幅线刻画所展现的女性形象,进行了中西诸多艺术元素的对比分析,指出这些画作采用外来西方艺术手法,描绘装饰在皇后石椁上的宫廷女性形象,作品集中表现出唐代流行的"拂菻样"风格以及宫廷匠师新的艺术审美观,是"中体西术""东魂西技"的典型艺术杰作。     

“文革”时期工业建设中引进技术基础上的创新

文化大革命和三线建设时期,技术创新体系再次陷入混乱。但中国赶超世界先进技术的信心和决心依旧。在已有引进技术的基础上,中国的国防尖端技术和其他重大技术取得了一定成就,但整体工业技术的改进或创新趋于停滞。这种技术发展的极端不平衡既是技术创新体系混乱、对外经济技术交流中断、可借以发展为新技术的技术源过于陈旧的结果,也和当时实行的与国家资源状况不相适应的重工业优先发展战略不无关系。     

法门寺唐“捧真身菩萨”艺术原型再探

<正>法门寺地宫出土文物中被定名为"捧真身菩萨"的鎏金银造像,不仅是造型传神的宗教宝物,也是精美绝伦的艺术珍品,学术界一直认为这件文物是佛教宗教仪式中最具典型的代表作,甚至     

考古学如何走近公众——读《最早的中国》

<正>近年来,考古学与公众的关系成为考古学家们热议的话题,越来越多的考古学家开始意识到"考古学知识的普及与文化的寻根正在变得更加重要"①,而且认为"考古学家在普及教育中有着义不容辞的责任"②。但是,考古学是一门专业性很强的学科,加上学科传统、研究重点以及理论方法的