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1.
《文物保护研究》2013,58(1):53-58
AbstractThe presence of soluble salts in stone does not always lead to decay. Salt crystallization can be disruptive or cementing depending upon the pore structure of the stone and the crystallization pressure that develops within the pores. In this paper pore measurements on six types of stone and calculated pressure values are used to explain the decay morphology, and to show the correlation between the observed alteration processes and the crystallization pressure, which depends upon the pore-size distribution. 相似文献
2.
ABSTRACT Sandstone is a common sedimentary rock that is easily carved due to its weakly cemented fine grains and relatively low strength. Therefore, numerous large-scale grottoes in China are made of sandstone. However, these sandstone cultural heritage structures are often seriously damaged due to temperature and humidity changes, air pollution, biodeterioration, and repeated dissolution and crystallization of soluble salts. In general, it is imperative that a consolidant capable of providing cohesion by infilling pores between the stone grains is synthesized. In recent years, it has been reported that using organic consolidation materials for sandstone protection comes with various negative effects, such as a short lifetime, poor compatibility, and preservation damage. Using inorganic consolidation materials to protect sandstone seems to be one of the research trends for the future. Herein, this paper introduces a permeable, inorganic magnesium-based material (MMH solution) for silica sand consolidation. To assess this consolidant, the paper investigates the influence of varying molar ratios of MgO:MgCl2·6H2O:H2O on properties such as penetration depth, consolidation weight, colour variation, and compressive strength. The results demonstrate that the molar ratios of MgO:MgCl2·6H2O:H2O can significantly affect the consolidation performance. Additionally, it is believed that the MMH solution of MgO:MgCl2·6H2O:H2O?=?5:1:16 can be successfully used for the consolidation of silica sand, as the cubic specimens’ surface micrographs show good compatibility between the consolidation product and sand grains. Experiments (i.e. weight loss rate and mineralogical compositions analysis) are performed to evaluate the cubic specimens’ water resistance properties after being immersed in water. Furthermore, the consolidation material’s failure mechanism as a self-sacrificing material is preliminarily analyzed. Results indicate that MMH solution is a promising conservation material that shows great potential for consolidating severely weathered sandstone. 相似文献
3.
ABSTRACTIn the Mogao Grottoes of Dunhuang, China, the ambient relative humidity (RH) fluctuation in the caves is the main cause for the deterioration that has been observed, especially the deterioration of the earthen plaster and wall paintings linked to the presence of NaCl and Na2SO4 salt contaminants. To help identify the mechanism responsible for this salt-related deterioration and provide a theoretical basis for the development of a preventive conservation regime, this study addressed the basic moisture adsorption mechanisms of earthen plaster with soluble salts by taking an experimental approach. It is shown that, as ambient RH increases, the moisture adsorption process of the plaster containing the soluble salts can be regarded to have three basic stages, as evidenced by the results of the moisture adsorption tests performed on earthen plaster samples with different NaCl or Na2SO4 contents at various humidity levels. The moisture adsorption mechanism and its determining factors at each stage are also analysed. In addition, it is suggested that the hygroscopicity of the plaster structure and the interaction between the different kinds of salts in the plaster, which makes the dissolution or hydration of the salt in the plaster pores much easier, should be considered more seriously regarding increases in the ambient RH in the caves. 相似文献
4.
Ainara Zornoza-Indart Paula Lopez-Arce Karima Zoghlami Nuno Leal Joaquim Simão 《文物保护研究》2013,58(2):73-89
ABSTRACTCalcarenite stone samples from a historic building (Bizerte, Tunisia) were collected and treated under different environmental conditions with several consolidating products: alkoxysilane (ethyl silicate), a surfactant-templated novel sol–gel, Ca(OH)2, and SiO2 nanoparticles. These were subjected to marine aerosol accelerated aging cycles and studied by several non-destructive tests and techniques to assess the stability of the products. Results show that weathering caused by salt crystallization is not inhibited but it is slowed down due to the enhancement of superficial mechanical properties (surface cohesion and micro-hardness) achieved after one month of treatments application. A high or low relative humidity of the consolidation environment significantly affects the final mechanical and aesthetical physical properties and therefore conditions the durability of the treated substrates, even producing higher damage than observed in the blank specimens, depending on the product. 相似文献
5.
时间和空间是可移动文物的基本维度,也是可移动文物数据的重要属性和内容。对可移动文物时空数据进行组织与管理,有利于促进可移动文物的研究与利用。针对可移动文物的时间与空间信息特征,在对可移动文物进行时空变化类型和驱动因素分析的基础上,基于数字人文的方法与技术,提出了面向可移动文物的时空数据模型,并将其应用于绘画类可移动文物。基于该模型可以有效地组织与管理绘画类文物的时空信息,表达绘画类文物的时空演变过程,包括与绘画类文物时空变化相关的关键人物与驱动事件,对可移动文物的保护与发展具有一定的意义。 相似文献
6.
《文物保护研究》2013,58(4):281-297
AbstractCellulose poultices are frequently used in stone and wall painting conservation for the purposes of soluble salt extraction, consolidation and cleaning. They have the reputation of being easy and pleasant to work with, have a neutral pH, high water absorption and plasticity, exhibit good conformance and adhesion to the substrate, and in most cases leave minimal residues after clearance. The cellulosic materials from which they are composed range from cotton wool, blotting paper or newspaper, to cellulose powders, the latter now by far the most common form of cellulose used today by conservators. Drawbacks of these products include poor water retention when applied to vertical surfaces, a tendency to redistribute salts further into the object substrate, and poor long-term treatment effectiveness for salt extraction. Hence cellulose poultices are used frequently due to good working properties, but apparently are in some situations not very effective. In this paper, existing knowledge of these poultices is outlined, followed by investigations undertaken to fill some of the knowledge gaps. Investigations include characterization of poultice properties such as pore size distribution and workability, and of moisture transport processes within poultice/substrate systems including moisture penetration depth, moisture distribution, and poultice shrinkage during drying. Cellulose powder products known under the trade name Arbocel®, extensively tested and used in conservation over several decades, were a particular focus. Resulting guidelines include counter-intuitive measures such as (when used for salt extraction purposes) the use of thinner poultices to reduce drying shrinkage and salt redistribution further into the substrate. The relatively uniform pore size distribution (around 10 μm) of Arbocel® poultices makes them more appropriate for salt extraction on substrates with a medium-coarse pore size (i.e. 15 μm and above), while on fine porous substrates (10 μm and below), the extraction will not be as efficient. 相似文献
7.
《文物保护研究》2013,58(1):24-29
AbstractOptical and electron-beam microprobe examination of pairs of calcite crystals, mounted approximately 50 microns apart and then immersed for various times in solutions containing a barium compound and urea, showed that these crystals were cemented together by the formation of an adherent bond between the calcite substrate and the witherite filling the void space between the crystals. The bonding material was found to be composed of a series of solid solutions of barium calcium carbonate, high in calcium content at the original surface and increasing in barium content as the distance from the original crystal surface increased. The relatively rapid rate of reaction suggests that the formation of the solid solutions proceeds by a co-precipitation mechanism. The formation of the solid solutions is thought to occur most readily in pores and cracks where the calcium ions generated by the dissolution of calcite cannot readily diffuse into the bulk solution. Application of the barium hydroxide-urea treatment to the preservation of decayed calcareous stone is reviewed. 相似文献
8.
[目的/意义] 元数据的开发与应用是文物数字化项目中的重要内容,也是项目成败的关键。随着国内文物数字化保护项目的进一步开展,在开放信息环境下构建一套完整的元数据开放机制,来保障文物元数据的有效性、扩展性和互操作能力显得尤其重要。[方法/过程] 借助生命周期理论,深入分析文物数字化保护项目中文物元数据的整个生命周期阶段以及各阶段所要解决的问题、参与的角色,提出不同生命周期阶段应采取的开放建设机制,并以台湾数位典藏国家型科技计划下的MAAT案例为例,对该项目的元数据工作内容进行分析,重点分析其中值得借鉴的部分。[结果/结论] 借助生命周期理论研究文物元数据制定及应用过程中的开放机制,具有很强的针对性和可操作性,能更好地保证整个运行周期中文物元数据的有效性、扩展性和互操作能力。 相似文献
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10.
First aid for flood-damaged paper using saltwater: The inhibiting effect of saltwater on mold growth
《文物保护研究》2013,58(3):164-171
AbstractWith the aim of developing a new easy-to-use method for rescuing flood-damaged paper, the effect of saltwater on the inhibition of fungal growth on paper was investigated. This procedure could be used instead of, or assisted by freeze drying. Cellulose-digesting Trichoderma reesei, three types of fungi representative of fungi growing on paper (T. reesei, Aspergillus terreus, and Aureobasidium pullulans) and various naturally airborne fungi were cultured on cellulosic materials in liquid media containing artificial seawater with different salt concentrations. The addition of salts successfully inhibited the growth of T. reesei on microcrystalline cellulose at the concentration of 3.2% (m/m) or higher. The critical salt concentration, 3.2%, is within the general range of salt content in seawater. Other solutions of salts similar to sodium chloride also inhibited fungal growth. Although the observed growth-inhibiting effect was attributed to the high osmotic pressure of the salt solution, physiological effects depending on ion species used were also considered to be possible. The growth of all three types of fungi on copy paper was inhibited effectively when the salt concentration was increased. The growth of various fungi on pure cellulose, with enough oxygen supplied to pores, was completely inhibited (as assessed by visual examination) for 24 days at salt concentrations of 3.5% (m/m) or greater. The fact that the effect of saltwater on cellulosic materials was observed even under optimum medium conditions implies that fungi would be considerably inhibited on flood-damaged paper immersed in saltwater. This method is a promising first aid measure when circumstances do not allow for flood-damaged paper to be dried immediately. 相似文献
11.
Roberto Giustetto Elena Maria Moschella Mariano Cristellotti Emanuele Costa 《文物保护研究》2017,62(8):474-493
An in-depth scientific survey revealed the deterioration mechanisms affecting the ‘Santa Maria della Stella’ church in Saluzzo, Italy, where various salt crystallization processes are strongly damaging the building materials and artworks. Rainwater seepage permeates the vault and interior, causing: (1) epsomite growth as interstitial columnar crystals (resulting in pictorial coating detachment) or superficial, powdery efflorescence; (2) formation of nesquehonite/hydromagnesite crusts on wall paintings; and (3) nitratine growth causing pigment staining and detachment. These processes involve selective Mg2+ mobilization from magnesian-lime mortars and bacterial-induced formation of nitrates from guano, with consequent precipitation of degrading salts. The study confirms how characterization of all deterioration agents is fundamental to planning a viable cultural heritage conservation and restoration programme. 相似文献
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13.
《文物保护研究》2013,58(4):197-204
AbstractThis work combines our observation that the details of marble statues that have already been lost from the calcite surface are preserved in the gypsum layer, with our research on the mechanism of marble sulfation, to lead to a consolidation of the gypsum, transforming it back to calcium carbonate (calcite) using carbonate ions in solution. Our research shows the mechanism of the conversion of gypsum to calcite, the rate determining steps being the desorption and diffusion of CO2?3 We found that the reproduction of the surface detail and the improvement of the mechanical properties was very satisfactory. 相似文献
14.
《文物保护研究》2013,58(3):148-152
AbstractMineralogical changes which occur during the reaction of copper(II) chloride with carbonate in aqueous solution have been investigated, and compared with those involving copper(I) chloride, nantokite, CuCI, and copper artifacts coated with malachite, CU2CO3(OH)2 The reactions observed and the products obtained are seen to have implications with respect to the use of aqueous sodium carbonate solutions to stabilize archaeological copper objects. The frequent observation of the mineralogically rare species chalconatronite, Na2Cu(CO3)2·3H2O, on the surface of treated objects is readily explained by known reaction chemistry. Its formation can be minimized by washing the object after treatment. 相似文献
15.
康晓璐 《自然科学博物馆研究》2023,(4):5-14
作为拥有百万藏品、开展数字化较早的博物馆之一,故宫博物院管理着大量的文物及其产生的数据。目前,因现存数据存在数量庞大、多源异构且较为分散的现象,导致利用这些数据制作的数字内容难以被全面管理、利用率变低。为改善这一现状,故宫引入英国数据策管中心数据策管周期模型,建立数字服务设计与数据策管并行的工作机制,尝试在实践工作中通过搭建一站式数字服务平台,对数字内容的管理及利用效率产生积极作用。 相似文献
16.
《文物保护研究》2013,58(4):222-226
AbstractLarge ethnographical collections sometimes contain examples of preserved human heads. There are those from the Maori of New Zealand, the well-known Jivaro Indian shrunken heads, and others from Papua-New Guinea. The article describes the preservation process as practised in Western Papua by the tribal craftsman, and then the problems of conservation in the museum laboratory. The latter include the cleaning of the skin, and the painted areas of the face, with the non-ionic surface-active agent Lissapol N in distilled water, followed by consolidation of the painted surface with an application of 2 % soluble nylon in industrial methylated spirit. Clay and fibre within the head were consolidated with a 5 % solution of the polymethacrylic ester Bedacryl 122X (I.C.I.) in xylene; and the fibre ear ornaments, after cleaning with Lissapol N, were consolidated with a 5 % solution of soluble nylon in industrial methylated spirit. The specimen was fitted with a specially made polythene cover, and stored in an individual box. 相似文献
17.
Salt crystallization is recognized as a major cause of damage to porous building materials, threatening the sustainable preservation of our valuable built heritage. Unfortunately, the crystallization behavior of the detected salt mixtures is complex and not fully understood. While the deliquescence points of single salts are well documented, this is not the case for salts in a mixture where one is confronted with the presence of different cations and anions. In this paper the salt content of the murals and the limestone tracery of the main entrance porch from the sixteenth century church of St. James in Liège, Belgium is investigated and related to the climatic conditions of its environment. Concerning the salt load, the research consists of hygroscopic moisture content measurements, quantitative ion analyses, and the prediction of phase equilibria using the thermodynamic model ECOS/RUNSALT. This model can predict the salt crystallization sequences of a particular ion mixture. The output is mathematically evaluated with collected temperature and relative humidity data, which enables the calculation of the number of salt crystallization–deliquescence cycles. The results show that even small amounts of salts can cause damage over a long period of time when the environment causes frequent cycles of crystallization–deliquescence over time. It is shown how a mixture of small amounts of (double) salts, including hygroscopic ones, can have a significant effect on the decay of historic building materials in the case of daily changing climatic conditions and periods of extreme drought. As a result, the crystallization of double salts and hygroscopic salts such as calcium nitrate cannot be ignored. The scientific method and the results are described. 相似文献
18.
《文物保护研究》2013,58(1):63-64
AbstractWhite crystals have been found to grow on the surface of a number of wax artifacts. Analysis was carried out on samples of wax and crystals taken from a Victorian wax fruit arrangement displaying crystalline growth. The possible relationship between crystallization, cracking and changes in temperature is explored. 相似文献
19.
《中图法》第五版中的同书异号和异书同号现象分析 总被引：1，自引：0，他引：1
于新国 《图书馆工作与研究》2011,(6):67-69
文章对《中国图书馆分类法》第五版"G81世界各国体育事业"类两组同书异号现象和"K87中国文物考古"类一组异书同号现象进行了分析和探讨。 相似文献
20.
《文物保护研究》2013,58(4):284-286
AbstractThe widespread occurrence of thecotrichite, Ca3(CH3COO)3Cl(NO3)2·7H2O, in the museum environment is explained theoretically by construction and examination of its phase diagram. Thecotrichite formation was simulated in the laboratory to identify the key factors involved in its production. This efflorescence occurs on porous limestone or calcareous artefacts such as pottery, stored in wooden cabinets that generate acetic acid vapour. Salt production depends on the moisture content of the object and the concentration of acetic acid in its surroundings. Furthermore, for thecotrichite to form the artefact must contain soluble chloride and nitrate salts. 相似文献