巴蜀带斑纹兵器的锈蚀产物分析及机理探讨

带斑纹兵器是巴蜀兵器的一大特色。由于表面有斑纹的青铜兵器锈蚀与一般青铜器锈蚀有所不同,必须针对其特殊性进行锈蚀机理的研究,才能对症下药,达到有效保护的目的。应用矿相分析、SEM EDS、XRD等分析手段对几件巴蜀带斑纹兵器表面与截面锈蚀产物进行分析,并与非斑纹锈蚀进行比较;对斑纹与非斑纹的锈蚀机理进行探讨。分析结果表明,斑纹的锈蚀产物主要是SnO2,其在兵器斑纹表面形成钝性保护膜,防止其进一步腐蚀,对斑纹下面的基体有一定的保护作用。非斑纹层锈蚀向斑纹层下面的基体扩展,膨胀是造成斑纹层凸起甚至脱落的主要原因,对斑纹兵器保护的关键是控制非斑纹层锈蚀的进一步发展。     

The effect of soil conditions on the long-term corrosion of buried tin-bronzes and copper

The object of this work was to relate the corrosion of tin-bronzes to the chemical condition of the soil in which they have been buried, most of them since the Bronze Age. Naturally, it was not easy to obtain recent hoards with their related soils, and considerable reliance had to be placed on recorded finds by taking recent soil samples from sites on which hoards were found over a hundred years earlier. Even so, with the exception of peat, a reasonable relationship appears to exist between the pH of the soil and the state of the metal. Acid soils are aggressive to metals and alkaline soils are benign. In no cases were sulphate reducing bacteria active in promoting corrosion. In the main, peat and peaty soils were benign in spite of their acidity, probably due to the protective action of polyphenols.     

铜片除锈强度考察与缓蚀效果分析

在青铜器除锈过程中,既要除去有害锈及其他杂质,又不损伤青铜器原貌,这就需要掌握一定的度。本研究用失重法定量地考察了不同除锈法和不同除锈剂对铜钱的除锈强度。结果表明,物理除锈法与化学除锈法均有明显的失重率。化学除锈中,5%左右的冰醋酸有较高的除锈强度。采用不同组合的BTA缓蚀剂对铜片进行保护,通过Tafel曲线分析其保护效果,以1.5%浓度的BTA与2%H_2O_2的组合液缓蚀效果明显。经盐雾腐蚀试验对此结论进行了验证。     

出土饱水木质文物的微生物腐蚀及防腐措施

在南方保存完好的出土木质文物大都处于饱水状态.出土后因为水和氧气的参与,在水解作用、微生物腐蚀等诸多因素的作用下,木质文物逐步被降解而变得腐朽.为此,本文从木质文物的微生物腐蚀机理着手,提出控制水活度的办法、控制氧气量、毒化微生物赖以生存的养料三种途径来防止或延缓木质文物的腐朽,以等待将来更好的脱水定型方法出现.     

模拟青铜器样品在典型电解质溶液中的电化学行为研究

为了具体探讨青铜器不同相组织的腐蚀状况,采用电化学测量技术研究模拟青铜器样品在五种典型电解质和模拟土壤溶液中的腐蚀行为。实验结果表明,在氯化钠、硫酸钠、磷酸钠、氢氧化钠、碳酸氢钠以及模拟的土壤溶液中,青铜器组织中的α相比δ相及(α δ)共析体组织更容易发生腐蚀。介质的pH值以及不同离子对青铜器不同相组织的腐蚀行为影响很大。     

Stochastic Seismic Response of Pipelines with Corrosion

For aging pipelines, corrosion gradually appears inside and outside during in-service time. However, because the uncertainty characteristics of the soil around the pipeline and conveying material in the pipeline, the generation and development processes of the pipeline corrosion would be stochastic processes. This background must be taken into account in the seismic response analysis of the pipeline. In this article, using Markov chain with absorbing barrier, a model simulating the evolution of the pipeline corrosion is presented. This model divides a pipeline into several segments and obtains the distribution probabilities of the cross section areas of the segments. Elastic foundation beam method and random perturbation method are used to obtain the seismic response of the pipeline with corrosion. To validate the proposed method, two pipelines are investigated in detail. The mean and standard deviation of the displacements and stress of the pipeline under earthquake are evaluated by the proposed method. Also, the results of one pipeline are compared with Monte Carlo random simulation. The numerical results show that the proposed model can reasonably predict the seismic response of the pipeline with corrosion.     

Application of Wavelet Transforms on Characterization of Inelastic Displacement Ratio Spectra for Pulse-Like Ground Motions

In this article, a simple and effective wavelet-based procedure is implemented for describing principle features of a special class of motions, pulse-like ground motions, on inelastic displacement ratio spectra (IDRS). The computed spectra supply a simple estimation of maximum inelastic displacement demand from the corresponding elastic one. The results of analysis in this work provide a suitable platform for quantification of pulse effects into IDRS and highlight the need to better understanding of this effect on demand estimation. It is concluded that the pulse has a significant influence on IDRS of pulse-like ground motions for systems with high ductility level.     

Maximum Possible Ground Motion for Linear Structures

This article develops a method to generate ground motion time histories that maximize the response of a given linearly elastic structure. The root mean square (RMS) level of the input power spectral density (PSD) is used as a strong motion parameter. It is related to seismological data that is readily available. An empirical relation to estimate RMS value of the PSD from peak ground acceleration, magnitude, rupture distance, and shear wave velocity is derived from world-wide strong motion data. The ground motion is obtained by solving the inverse problem such that the structural response is maximized under the constraint of fixed value of RMS level of the input PSD enforced using a Lagrange multiplier. The proposed methodology is illustrated for a single-degree of freedom system, a six storey building and an earthen dam. It is shown that the critical PSD obtained in all the cases is a narrow band process resulting in stochastic resonance and not a Dirac-delta function with the entire energy of the system concentrated at its natural frequency. Moreover, the critical excitation samples generated using this critical PSD resembles actual earthquake acceleration time histories.     

国保单位公布背景与演变

每一批国保单位受当时的社会背景、文物保护理念等的影响,都有其鲜明的特点和时代烙印,都在不断地借鉴和融入新的文物保护理念。本文对第一至六批国保单位公布的历史背景进行回顾与综述,以期探讨国保单位的发展脉络,以及国保单位在社会历史影响下所形成的特点。     

福建唐代陈元通夫妇墓出土银质文物的微观结构分析

为了解陈元通夫妇墓出土银质文物的破损状况,更好地对文物进行处理.利用金相、XRD、SEM-EDS、显微硬度分析等,对其进行了微观形貌分析.确定了腐蚀产物,观察到几种不同的腐蚀形貌,揭示了银质文物易脆裂的内因.提出保护处理文物时,对银制品的脆性问题要给予更多关注.