关于青花起源的思考

关于青花的起源,长期来一直有中国起源说和外来技术影响说两种意见。本文着重从低温釉陶生产技术源流和对青料的使用出发,论证了最早出现在巩县窑的唐青花瓷器,只是北魏以来低温釉陶生产技术在新条件下的新产物。认定唐青花的出现是外来绘画理论和绘画技术影响中国艺坛的结果。     

Atmospheric deterioration of Qin brick in an environmental chamber at Emperor Qin's Terracotta Museum, China

Potential mechanisms for the changing appearance of Qin terracotta was evaluated on simulated bricks with, SO₂, NH₃, O₃, and a NH₃/O₃ mixture for total dosages of 2.2–5.4 ppm-years. Changes in the surface composition and appearance were evaluated with scanning electron microscopy/energy dispersive X-ray analysis (SEM–EDX) and X-ray photoelectron spectroscopy (XPS). No observable changes with O₃ exposure were found. Sulfate as sulfur and ammonium as nitrogen increased by 1.2 at% and 0.8 at% of the surface deposit as determined by XPS. O₃ did not have a detectable effect by itself, but when combined with NH₃, NO₃ as nitrogen increased by 1.5 at%, indicating a strong oxidation of NH₃ to nitric acid. The combination of outdoor O₃ infiltration with indoor NH₃, presumably from the visitors, appears to have a greater potential for damage than either pollutant by itself. SEM–EDX mapping of the surface showed sulfur associated with calcium and magnesium compounds after SO₂ exposure, but not before. More detailed microscopic examination showed this primarily in the form of gypsum, especially near cracks and pits in the surface. Both of these mechanisms are probably among the causes of changes in terracotta appearances since they were unearthed in 1974.     

低温竹炭净化文物保存环境空气中氮氧化物的探索

NOx是文物保存环境的一类重要的污染物,近期采用资源丰富、价格便宜的竹材及竹炭作为吸附剂去除污染物成为热点.本工作采用低温竹炭净化低氮氧化物,并对效果的影响因素进行了探讨,使用扫描电镜对低温竹炭表面形态进行了研究.研究表明,低温竹炭处理浓度在133～457 μg/m3NO时,处理效率可以达到84%～94%,处理浓度在82～453 μg/m3NO2时,处理效率可以达到93.3%～97.7%.当NO和NO2同时存在时,NOx在500 μg/m3时(NO:NO2=2:1),NO的处理效果下降,仅能达到44.7%,但是NO2的处理效果变化不大,仍可以达到98%.     

Petroleum type determination through homogenization temperature and vapour volume fraction measurements in fluid inclusions

Physical parameters of petroleum‐bearing fluid inclusions such as bulk density (ρ), molar volume (V_m), vapour volume fraction (?_vap) and homogenization temperature (T_h) are essential information to model petroleum composition (x) in inclusions and to reconstruct palaeotemperature and palaeopressure of trapping. For the main petroleum types contained in a fluid inclusion, we can follow how ?_vap and T_h are simultaneously influenced by a change of bulk density in a ?_vap versus T_h projection. We have correlated T_h and ?_vap for different petroleum compositions for a large range of bulk density values. However, postentrapment events under new pressure (P) and temperature (T) conditions can greatly modify the initial fingerprints of physical conditions and chemical composition of fluid inclusions. Re‐equilibration is frequent, especially in the case of fragile minerals. Stretching and leakage phenomenon have been simulated using the Petroleum Inclusion Thermodynamics (pit ) software, from virtual petroleum inclusions with known hydrocarbon composition. The aim of these simulations is to understand how ?_vap and T_h evolve with these re‐equilibration phenomena, with respect to the oil composition. Results of stretching simulations show a characteristic increase of T_h and ?_vap along correlation curves, with the curve shape dependent on petroleum composition. Leakage simulations show an increase of T_h and a smaller increase or even a decrease in ?_vap. Consequently, the better preserved inclusions in a given population can be presumed to be those that have the lowest T_h. Applications of T_h and ?_vap measurements of natural inclusions in calcite and in quartz showed that the fragility of the host mineral is a key factor allowing the recording of post‐entrapment events. Inclusions that have stretched or leaked are identified and the best preserved inclusions selected for evaluation of P–T–x trapping conditions. Moreover, petroleum types trapped in inclusions can be identified from ?_vap and T_h measurements without compositional modelling.     

论北宋开封地区的气候变迁及其特点

北宋开封地区的气候,绝大部分时间表现为继唐代以来我国气候变迁史上第三个温暖期的延续。其转变为第三个寒冷期的时间不是如近几十年来学者们承竺可桢所说的北宋前期,而是在北宋后期的徽宗初年。建中靖国元年前后,该地气候突然发生明显变化而进入了新的寒冷期。其间尽管这里的气候在徽宗、钦宗年间曾出现过由温暖期向寒冷期的突变,但总体上是一个渐进的变化过程。在当时每一段温暖期与另一段寒冷期气候交替变化的周期中,每一个较长时间的气候变化周期内都有若干个气候暖、冷交替变化的短周期,甚至在每一个短的气候暖、冷变化的周期内还有一些特别偏寒冷或偏温暖的年份。     

Evolution of Temperature and Moisture Fields in Charles Bridge in Prague: Computational Prediction and Measurements

Charles Bridge in Prague, founded in 1357, is one of the most prominent historical structures in Europe. It interconnects two Prague districts, the Lesser Town and the Old Town districts, separated by the Vltava River. In the past, the bridge underwent a variety of repairs and retrofits. Within the framework of the moderate repair carried into effect in 2007 to 2010, a measuring system was installed in the bridge, and the temperature and moisture content at selected gauge points have been continuously monitored for a period of 2 years. This article presents non-linear, fully coupled modeling of both fields utilizing a parallel version of the simple finite elements (SIFEL) computer code. Its cogency is validated against experimentally obtained data that serve as inputs for the second stage of a thermo-mechanical analysis—the detailed and mechanics-oriented simulations of the bridge as a whole.     

Monitoring the Near‐surface Urban Heat Island in Beijing,China by Satellite Remote Sensing

Urban heat island (UHI) effect is an important impact factor of the regional climate and ecological environment. How to observe and analyse the spatial distribution of UHI has become an important issue of urban environmental research. In this paper, the near‐surface air temperature of Beijing was derived based on the Landsat/TM satellite imagery on 26 July 2011 to study the near‐surface UHI. A statistical model at 195‐m window size was established to estimate the air temperature, using land surface temperature, normalized difference vegetation index, altitude, and surface albedo as independent variables. The mean absolute error (MAE) of the model was 0.87°C, and the R² was 0.66, indicating that the method can be used to effectively estimate the air temperature. The air temperature distribution obtained from remote sensing revealed that the UHI effect in Beijing was very significant and showed a concentrated pattern. The heat island intensity was stronger in the southern part than in the northern part of the city. In addition, the relationship between the air temperature and impervious surfaces was analysed. The air temperature increased with increasing impervious surface coverage, and the rate of change depended on the impervious surface coverage. When the impervious surface coverage was below 40 per cent, the temperature increased rapidly with increasing impervious surface coverage, and when the impervious surface coverage was above 40 per cent, the temperature increased slowly. This study provides a new approach to monitor near‐surface UHI and reveals its relationship with impervious surface, providing a scientific reference for urban planning and environmental assessment.     

天津博物馆文物保存环境调查与监测分析——以2015年1月监测数据为例

为了解天津博物馆文物保护环境状况,选取天津博物馆展厅内的部分展柜微环境为监测分析对象,利用无线传感监测系统对文物保存环境进行监测,监测日期为2015年1月份,监测参数包括展柜内的温湿度、光照度、紫外线和空气污染物。在数据分析过程中结合文物保存环境监测和控制方面的若干问题进行了探讨,对展柜的调控效果进行了分析。通过分析发现:独立加湿机控制的独立展柜相对湿度介于60.4%~63.3%,相对湿度偏高,建议展柜内配合一定量的调湿材料一起控制;光照度在闭馆时为1.84lx,开馆时介于43.96~52.22lx,开馆时紫外线强度介于0.02~0.06μW/cm²,基本能够满足《博物馆照明设计规范》的要求;展厅内二氧化碳浓度受观众人数的影响,在12∶00~14∶00浓度达到最大值,随后又不断降低,VOC浓度在展柜内存在累积增加现象。调查分析结果可为提高文物保护水平提供参考。     

苏家村遗址烧土样品的过火温度研究

烧土制品作为最早的人工建筑材料,使人类的居住环境得到了根本性的改善。然而,学界关于烧土建筑的成因存在人为烘烤处理、缘自火焚、废弃习俗等多种观点。通过科技手段研究烧土制品的过火温度,有助于科学分析烧土建筑的成因,探讨与之相关的建筑工艺,丰富史前建筑史研究。磁学研究表明,考古遗址中的土壤及其他沉积物在受热后新生成了磁铁矿、磁赤铁矿等强磁性矿物导致磁性显著增强,且矿物成分和磁性几乎不会再发生变化;但当重烧的温度接近或大于原始烧成温度时,样品中原始矿物的破坏或新矿物的生成,会引起矿物磁性的改变。基于这一原理,实验室内分析受热黏土的磁化率随再加热温度的变化特征,可反映烧土制品的过火温度。苏家村遗址是大汶口文化晚期至龙山文化中期早段一处重要的聚落遗址,遗址中第5层为厚约20～40 cm的红烧土层且覆盖整个遗址,推测为房屋倒塌造成的建筑垃圾堆积层或人为堆积层,出土大量烧土块。本研究利用X射线衍射分析法、X射线荧光光谱分析法和磁化率法等对苏家村遗址出土的烧土样品开展了组成及构造特征和样品的过火温度的综合分析。结果表明,苏家村遗址烧土样品中的白灰层中人为地添加了白色陶土原料,土层中有意地添加了植物残骸作...     

Leftovers: The presence of manufacture-derived aquatic lipids in Alaskan pottery

Lipids preserved within the walls of ancient pottery vessels are routinely analysed to reveal their original contents. The provenience of aquatic lipids in pottery is generally connected to vessel function (e.g., for cooking or storing fish, shellfish and aquatic mammals). However, ethnographic reports from early historic Alaska mention the use of aquatic oils for waterproofing low-fired pottery. Results of lipid residue studies on Alaskan pottery reflect an exclusive function of pottery to process aquatic resources. However, can one be sure these residues are the product of vessel function and not a remnant of the manufacturing process? The study presents the results of an experiment where the preservation of aquatic lipids during the firing process at different temperatures was measured. It was found that nearly all lipids were removed at firing temperatures of ≥ 400°C. Petrographic analysis of Alaskan pottery samples indicates that firing temperatures were generally > 550°C but < 800°C. The contribution of pre-firing manufacture-derived lipids to samples fired at these temperatures may be regarded as negligible. While the possible presence of aquatic lipids from post-firing surface treatments cannot be excluded, such treatments appear unnecessary for well-fired pottery.