张八岭群火山岩地球化学特征及其构造学意义

安徽滁州张八岭地区的张八岭群分为2组。一是下部北将军组,以千枚岩和片岩为主;二是上部西冷岩组,主要为一套变质火山岩系。张八岭岩群的细碧-石英角斑岩系主要发育于西冷岩组中,具多旋回特点。细碧-石英角斑岩系以石英角斑岩为主,细碧岩次之,角斑岩类稀少。该岩系的火山岩富碱、富钠,具双峰值特征,其主量元素、微量元素和稀土元素地球化学特征表明,它形成于非造山张性环境,为裂陷槽,是与晚元古代罗迪尼亚(Rodinia)超大陆裂解有关的岩浆作用的产物。     

黑龙江东部大三江盆地群城子河组和穆棱组时期重矿物特征及物源分析

应用数理统计及Q型聚类分析方法,对大三江盆地群主要盆地20口钻井早白垩世城子河组和穆棱组砂岩中的重矿物进行了重矿物ZTR指数、稳定指数以及组合特征分析.城子河组和穆棱组重矿物ZTR指数等值线图都具有由边部向中心逐渐增大的趋势,而这两个组的重矿物稳定系数整体也较低,反映出成盆初期重矿物稳定性弱的特点,并根据重矿物种类将研...     

Interpretation of channelized architecture using three-dimensional photo real models, Pennsylvanian deep-water deposits at Big Rock Quarry, Arkansas

Mapping geological details and interpreting three-dimensional geometries in a highly heterogeneous outcrop such as the exposure at Big Rock Quarry has been a continuous challenge especially because high vertical cliffs make access to most of the rocks difficult for direct geological observations. Previous interpretations of facies architecture were derived from gamma-ray profiles, a core and measurements made on two-dimensional photomosaics. This paper represents the first attempt of three-dimensional interpretation of the geometry and facies pattern of the Jackfork nested channel complex deposited at the base-of-slope.Examination of the photo real model of the outcrop with assigned lithologies allowed extraction of accurate 3-D qualitative, as well as quantitative (channel dimensions) geometric information. This facilitated interpretation and reconstruction of the submarine channel complex architecture making possible correlations of strata exposed on the two sides of the quarry.Most of the exposed vertically and laterally stacked channels are large, aggradational with well-defined axial regions overlain by matrix-supported breccia which grades upward into amalgamated sandstones. The thickness of the sandstone decreases toward the southeastern end of the quarry where more shale is present. The channel infill consists of thin-bedded sandstones interlayered with shale which overlain the breccia. The upper part of the quarry is made up of smaller, lateral migrating channels.Significant channel width and thickness variation can be recognized at outcrop scale. Thirty-eight identified channels are characterized by a relatively low aspect ratio (4:1 to 32:1) with channel dimensions ranging from 25 m to 314 m wide and 2 m-24 m deep. Bed thickness distributions of various facies show that the sandstone comprises a significant proportion (83%) of the total channel thickness, while shale and breccia represent about 8%, and 17% respectively. This yields a high net-to gross ratio of more than 80%.Compared to previous reconstructions our 3-D photo real model is more accurate and it can be used to calibrate simulation of processes in deep-water environments.     

沿海城市群城际快速轨道交通系统评价方法研究及应用

针对以交通客流预测结果为基础所提出的城市群城际快速轨道交通系统初步规划方案,通过建立基于系统效益、经济效益和社会环境效益等3个方面的指标体系,构建适合我国城市群交通发展现状和趋势的评价模型和方法,对城市群轨道交通系统的结构与功能进行衡量和评估,辨别系统发展程度,对规划线网进行评价,从总体上对城际轨道交通系统规划方案的可靠性与合理性进行验证。     

文人主导下的群体性办刊模式——20世纪40年代港版《文艺生活》的办刊模式及其省思

在20世纪40年代后期香港特殊的时空环境中,国内流亡文人与其所办刊物的生存方式是一个耐人寻味的话题。司马文森之于港版《文艺生活》月刊的办刊策略适时调整为文人主导下的群体性办刊模式,主要表现为出版资金的群体性支持,发行上的群众性和杂志稿源的群众性。这种独特的办刊模式不仅丰富了人们对20世纪40年代文学期刊办刊模式的认识,有助于人们更加深入地了解四十年代现代文学(尤其是华南现代文学)和现代作家的历史境遇和现代命运,而且对于当下一些文学杂志以及其他刊物的办刊策略和市场运作等方面具有后瞻性的意义和价值。     

城市道路环境PGEs含量分布

以乌鲁木齐市为研究区,分析了城市道路环境PGEs含量水平和分布特征,并探讨了其来源变化.样品经王水消解后由ICP-MS测定.研究结果表明:鸟鲁木齐市道路灰尘Rh、Pd、Pt浓度分别达到10.27(3.83～19.10)ng/g、100.49(20.94～244.9)ng/g、37.01(5.79～93.71)ng/g,...     

我国泛亚桥头堡群建设的战略研究

建设中国泛亚桥头堡群,促进亚洲次区域合作是全球化、市场化、区域经济一体化的必然趋势,是我国对外开放战略深入推进、改革开放重心由沿海向沿边扩展的必然要求.为此,应综合分析区位、资源等优势,以"威海"为中心,依托山东半岛,打造东亚东北亚区域合作桥头堡;以"北部湾、昆明"为两核,形成东南亚、南亚合作桥头堡;以"喀什"为中心,依托新疆腹地,打造中亚桥头堡.使泛亚桥头堡群承载作为国际物流与商贸中心,推进产业互补与合作,实施多元融合与交流,尝试创新国际新规则等功能;通过产业创新平台构筑、合作模式磋商、货币双边互换、文化创意共享等路径推进其建设.     

区域经济发展中的“狼群效应”——以郑州与泉州市为例

采用经济实力分析、基尼系数和区位商的方法,对郑州市与泉州市所辖县域经济体的"狼群效应"进行了定量分析.认为郑州市与泉州市所辖县域经济体发展水平普遍较高,各县市之间的差距相对较小,产业、部门各具优势,并且具有较强的互补性.这种区域经济发展中的"狼群效应"不仅能够避免极化理论的缺陷,而且能够增强区域的整体实力和竟争力.郑州市与泉州市所辖县市的这种区域发展策略,有利于减小地区差距,加强城乡联系,促进农民的就近就地非农转化,而且能够最终实现城乡共同富裕.郑州市与泉州市所辖县市的发展模式为当前广大中西部地区的县域经济发展树立了典范.     

Pre-industrial-potential and Last Glacial Maximum global vegetation simulated with a coupled climate-biosphere model: diagnosis of bioclimatic relationships

The global climate–vegetation model HadSM3_TRIFFID has been used to estimate the equilibrium states of climate and vegetation with pre-industrial and last glacial boundary conditions. The present study focuses on the evaluation of the terrestrial biosphere component (TRIFFID) and its response to changes in climate and CO₂ concentration. We also show how, by means of a diagnosis of the distribution of plant functional types according to climate parameters (soil temperature, winter temperature, growing-degree days, precipitation), it is possible to get better insights into the strengths and weaknesses of the biosphere model by reference to field knowledge of ecosystems.The model exhibits profound changes between the vegetation distribution at the Last Glacial Maximum and today that are generally consistent with palaeoclimate data, such as the disappearance of the Siberian boreal forest (taiga), an increase in shrub cover in Europe and an increase of the subtropical desert area. The effective equatorial and sub-tropical tree area is reduced by 18%. There is also an increase in cover of wooded species in North-Western Africa and in Mexico. The analysis of bioclimatic relationships turns out to be an efficient method to infer the contributions of different climatic factors to vegetation changes, both at high latitudes, where the position of the boreal treeline appears in this model to be more directly constrained by the water stress than by summer temperature, and in semi-humid areas where the contributions of temperature and precipitation changes may partly compensate each other. Our study also confirms the major contribution of the decrease in CO₂ to environmental changes and carbon storage through its selective impact on gross primary productivity of C3 and C4 plants and a reduction by 25% of water-use efficiency. Specifically, the reduction in CO₂ concentration increases the amount of precipitation necessary to sustain at least 20% of grass fraction by 50 mm/year; the corresponding threshold for trees is increased by about 150 mm/year. As a consequence, a reduction in CO₂ concentration considerably widens the climatic range where grasses and shrubs dominate.