宁安市渤海上京城发现的铜佛像

佛教是渤海国时期信奉的大教,遗憾的是至今尚未发现渤海留下的佛教典籍,但在上京龙泉府遗址内各寺庙址附近发现数量较多的渤海佛像.     

咸亨酒店与麦当劳的隐喻

长期以来,食物和饮食方式构成了人类学研究的传统议题。列维一斯特劳斯尝试在食物语言建立普遍的意义系统,玛丽·道格拉斯解读了膳食社会符号,萨林斯则分析了关于内部与外部、人类与野蛮的食物隐喻。阎云翔、郭于华、景军等也对中国饮食文化作了细致深刻的描述和分析。稍微不同的是,本文试图以咸亨酒店和麦当劳为例,检视全球化社会变迁进程中中国饮食消费社会空间和社会形式的演变过程及其社会文化后果。     

文物的赋存环境及其预防性保护问题

我国是世界上历史最悠久的古国之一,拥有为数众多的具有历史、科学、社会及经济价值的文物。本研究尝试综述了从文物与其赋存环境关系的角度,将文物赋存环境分为全曝露自然环境、半曝露自然环境及人工营造环境,通过分析赋存环境对文物的影响,探讨文物赋存环境的转化过程,提出不同环境条件下文物的预防性保护问题。     

土质文物盐害中硫酸钠的研究——从微观到宏观

土遗址和壁画遗址可溶盐主要为NaCl和Na_2SO_4,其中Na_2SO_4是破坏程度最严重的盐。一般认为,硫酸钠只有在温度、湿度变化时才不稳定,才发生得失结晶水引起的晶型及体积变化。为研究土质文物盐害的形成机制及内在原因,调研了全国几处典型土遗址和壁画遗址的盐害状况并取样分析。分析发现:1)土遗址和壁画遗址中硫酸钠的形貌、结构是动态变化的(无论在任何极端干燥环境甚至真空条件下);2)环境因素如温度、相对湿度的变化只是加剧上述变化进程。硫酸钠结晶析出时,其体积膨胀约4倍。这一系列的过程,深刻影响着硫酸钠的相变复杂性和对依存土质文物本体的破坏性。本工作从微观和宏观两个层面探讨了这些发现,并通过不同盐分(不同浓度氯化钠、硫酸钠)侵蚀破坏模拟试验、不同温度条件下模拟试验、不同相对湿度下模拟试验,从宏观层面印证了上述微观机制在土遗址和壁画遗址本体的外在表现。本研究发现土遗址中硫酸钠的形貌、结构是动态变化的,该工作弥补了以往研究和认识上的局限。本研究将对阻止、延缓及预测土质文物盐害的发生、发展提供科学参考。     

Spatial Distribution of City Tweets and Their Densities

Social media outlets such as Twitter constitute valuable data sources for understanding human activities in the virtual world from a geographic perspective. This article examines spatial distribution of tweets and densities within cities. The cities refer to natural cities that are automatically aggregated from a country's small street blocks, so called city blocks. We adopted street blocks (rather than census tracts) as the basic geographic units and topological center (rather than geometric center) to assess how tweets and densities vary from the center to the peripheral border. We found that, within a city from the center to the periphery, the tweets first increase and then decrease, while the densities decrease in general. These increases and decreases fluctuate dramatically, and differ significantly from those if census tracts are used as the basic geographic units. We also found that the decrease of densities from the center to the periphery is less significant, and even disappears, if an arbitrarily defined city border is adopted. These findings prove that natural cities and their topological centers are better than their counterparts (conventionally defined cities and city centers) for geographic research. Based on this study, we believe that tweet densities can be a good surrogate of population densities. If this belief is proved to be true, social media data could help solve the dispute surrounding exponential or power function of urban population density.     

Direct inversion of Young's and Poisson impedances for fluid discrimination

Seismic inversion with prestack seismic data such as amplitude variation with offsets (AVO) inversion is an important tool in the estimation of elastic parameters for predicting lithology and discriminating fluid in conventional or unconventional hydrocarbon reservoirs. The product of Young's modulus and density (Young's impedance, YI) and the product of Poisson ratio and density (Poisson ratio impedance, PI) show great potential in lithology prediction and fluid discrimination of unconventional resources such as shale gas or oil. The high quality requirements for prestack data in density inversion render the estimation of YI and PI arduous and inaccurate with a conventional prestack inversion approach. In this study, a direct AVO inversion approach is proposed to estimate YI, PI, and density directly from P‐wave seismic data. The linearized P‐wave reflectivity approximate equation in terms of YI, PI, and density is initially derived. Five models, including four typical AVO classes, are utilized to verify the accuracy of the derived linearized P‐wave reflectivity equation in comparison with the exact P‐wave reflectivity equation and the frequently used linearized reflectivity approximate equation involving P‐ and S‐wave velocities and density. Parameter sensitivity analysis illustrates that YI and PI can reasonably be estimated from P‐wave reflectivity if a decorrelation scheme is utilized in the inversion algorithm. In addition, a pragmatic AVO inversion using a Bayesian scheme is suggested for the direct inversion of YI and PI from prestack seismic data. Synthetic and field data examples demonstrate the feasibility of the proposed inversion approach in the estimation of YI and PI and show the potential of this approach in fluid discrimination.     

定边郝滩东汉壁画墓绿色底层颜料分析研究

本研究以定边郝滩东汉壁画墓中绿色底层为研究对象,采用偏光显微镜(PLM)、带能谱的扫描电子显微镜(SEM/EDS)、X射线衍射仪(XRD)和拉曼光谱(RS)分析了绿色底层的成分与物相,同时和四种已知国外绿土相比较,得出绿色底色为绿土,对其进行深入分析研究以期为考古学和后期文物保护工作提供科学信息。     

商代的楚蛮与西周初年的楚国

传说时代,江汉地区的古代居民为古三苗,三苗灭亡后,其遗裔在商周时代形成了楚蛮部族。商代楚蛮分布在以丹江库区为核心的鄂豫陕交界地区和汉东地区。西周初年,熊绎受封立国于楚蛮之地,汉东地区与楚国初封无关,则西周初年的楚国当在丹江地区,与丹淅说相合。     

改革开放以来广佛都市区空间扩展分析

利用遥感和GIS技术对改革开放以来广佛都市区的空间扩展情况进行分析,从1982年的地形图、1995和2008年的遥感影像中提取城镇建设用地和路网数据,从扩展强度、方式和效率等方面对其扩展情况进行定性定量的测度分析,发现:其建设用地具有扩展强度大、速度快的特点,但土地利用方式不甚合理,具有一定的低度不连续开发现象和较显著的道路沿线开发特征;扩展效率不高,新增用地的集约化程度、人口承载力度和经济产出水平均低于原有用地水平。这种高速、低效和无序的扩展特征表明其快速发展存在蔓延倾向。     

安徽淮北部分地区出土青铜器的铜矿来源分析

内容提要本文利用地球化学示踪的原理,以特征微量元素作为判别标志,对安徽省淮北部分地区出土的先秦时期铜器的铜料来源进行了初步分析,其中部分样品的铜料可能来自铜陵地区,有的可能来自铜绿山及其它地区。