一种饱水木质文物含水率无损检测方法的研究

含水率是评估饱水木质文物糟朽程度最常用的物理参数之一。目前含水率检测常用方法有烘干法、电阻法、近红外光谱法等,但这些方法或属于破坏性分析,或检测范围不适用。为寻找一种适用于饱水木质文物含水率的无损检测方法,基于饱水木材组成理论模型,建立了含水率与湿态密度、灰分含量三者之间关系,进而提出一种检测含水率的便捷方法——溶液密度法。采用上述方法对天长、淮北等地出土饱水木质样品含水率进行测试,并与烘干法测得标准值进行验证。结果发现两者数据较为接近,相对误差在10%以内,证明了该方法的可靠性。进一步研究发现,样品越糟朽,使用该方法获取的数据与标准值之间相对误差越小。说明该方法更适用于糟朽饱水木材含水率的检测。     

Blind tests in microscopic residue analysis: comments on Wadley et al. (2004)

In this comment, we critique a recent paper by Wadley, Lombard and Williamson entitled ‘The first residue analysis blind tests: results and lessons learnt’ (Journal of Archaeological Science 31 (2004) 1491–1501) as a means of assessing the role and utility of such blind tests. We find that apart from not being the first residue analysis blind tests, the tests conducted by Wadley et al. exhibit problems at each stage of experimental design. Most of the issues identified can be attributed to loss of experimental control, including lack of documentation of residues prior to blind testing and contamination of their samples. We suggest possible means of avoiding these issues in future microscopic residue analysis blind tests.     

微生物诱导碳酸钙修复汉白玉石梁裂缝试验研究

石质文物劣化后产生裂缝等病害,需要恰当的修复方法。本研究应用微生物诱导碳酸钙沉积技术修复汉白玉石梁裂缝,模拟石质文物裂缝修复。研究对象为带V型槽的非贯通和贯通裂缝的汉白玉石梁(尺寸为40 mm×40 mm×160 mm),修复方法为先注浆后自由下渗。通过对比石梁修复前后破坏荷载和强度的变化以及CT扫描技术可视化非贯通裂缝修复过程来评价修复效果。结果显示:修复后石梁裂缝表面致密光滑,颜色与母材相近,整体美观性好;非贯通裂缝修复后破坏荷载均有所增加,贯通裂缝修复后的抗折强度能恢复到原有强度的35.12%,均值为3.684 MPa,最高能达到5.234 MPa;CT扫描结果定性和定量均表明胶凝体密度随修复进行而增加,接触面修复质量弱于其他位置。     

Is It Hop? Identifying Hop Fibres in a European Historical Context

Hop (Humulus lupulus L.) is an ancient perennial crop plant, native to the Northern Hemisphere. The archaeological evidence dates back to at least the sixth century ad in Europe. Hop has been used for beer brewing, in sleeping draughts, as bedding and for antibacterial purposes. Less known is that hop fibres have also been used for textiles and paper. However, it is difficult to distinguish hop from other bast fibres. Here, we present a set of fibre features, which, when found together in an archaeological/historical material within a European context, provide a strong indication that the fibres are hop.     

Santa Maria di Collemaggio Church (L’Aquila,Italy): Historical Reconstruction by Non-Destructive Testing Techniques

The main goal of this work was the non-destructive testing (NDT) of an ancient fresco (15th century) preserved in the Santa Maria di Collemaggio Church (L’Aquila, Italy) and damaged after the 2009 earthquake. Active infrared thermography (IRT), near-infrared (NIR) reflectography and ultraviolet imaging (UV) were used. In addition, the state of the fresco prior to the earthquake was analyzed by electronic speckle pattern interferometry (ESPI), digital speckle correlation (DSC), raking light, tap, and chemical NDT techniques. The use of these techniques was important for the monitoring of new damages and for a comparison between the results over the years. Square heating thermography (SHT) data were processed using principal component thermography (PCT) and pulsed phase thermography (PPT) algorithms, in order to improve the defects’ signature and to reduce the impact of non-uniform heating and emissivity variations due to the painting’s pigments. A multi-analysis approach, segmentation operators and a specific data correlation method emphasize the overall study of the fresco. Furthermore, the facade and the high altar area were inspected by passive thermography and ground-penetrating radar (GPR), respectively. In the present case, the combined use of NDT techniques was useful to fill in the gaps in the construction history of the building.     

我国旅游业发展与经济增长的关系研究——基于不同省份的个体数据和面板数据分析

本文利用个体数据和面板数据的VAR模型和格兰奇因果检验,分析我国各个省份和不同经济区域的旅游业发展与经济增长的关系。基本结论是：从面板数据分析来看,总体上二者之间存在一种长期均衡和双向因果关系,但旅游业发展对经济增长的贡献要小于经济增长对旅游业发展的贡献;我国不同经济区域之间二者的因果关系表现出较强的地理差异性,东部发达地区“经济增长对旅游业发展的影响”远大于“旅游业发展对经济增长的影响”,中部地区次之,西部地区因果关系正好相反,东北地区为“经济增长影响旅游业发展”的单向因果关系;从单个省份的格兰奇因果关系看,仅13个省市的LGDP和LTOUR之间存在长期均衡关系,大部分省份存在双向因果关系,但在影响强度上有较大差异。     

Detecting modes in low-dimensional archaeological data

An approach to testing for modes in low-dimensional data, Silverman’s test, novel in an archaeological setting, is described and illustrated. ‘Patterns’ in archaeological data can be suggested by the presence of modes. Reassurance is needed that modes suggested by graphical analysis are genuine before attempting substantive archaeological interpretation. The test either provides such reassurance, or else guards against over-interpretation, particularly with small samples. Data on loomweight dimensions, lead isotope ratios, and ceramic compositions are used to illustrate use of the test, dealing with issues concerning outliers and small samples as they arise. The focus is on univariate mode detection.     

Finite element modeling of slug tests in an aquifer with stratigraphical and structural heterogeneities

Slug interference tests using an array of multilevel active and monitoring wells permit enhanced aquifer characterization. Analyses of these field test data rely on numerical inverse models. In order to provide synthetic data sets and to have a better understanding of the flow mechanisms, we used a three-dimensional finite element analysis (FEHM) to explore the effects of idealized, stratigraphical (strata) and structural (faults) heterogeneities with low permeability values on the transient head field that is associated with slug tests in an aquifer. Firstly, we tested our model on homogeneous aquifers and the effectiveness of our modeling strategies have been validated via the excellent agreement of our modeling results with those of the semi-analytical model of Liu & Butler (1995) . In our heterogeneity investigations, we embedded vertical and horizontal zones of lower permeability into a homogenous, isotropic, and confined aquifer to represent low-permeability faults and strata respectively. A slugged interval is located at the center of the aquifer. Effects of strata thickness and permeability contrast as well as other effects associated with the offset of low-permeability strata were explored. In particular, modeling results are represented by contour maps of peak travel time and maximum head perturbation of generated hydraulic pulses. Furthermore, various phenomena, such as real-time matrix diffusion, intermittent matrix–fracture interactions, and faster pulse arrival through a longer flow trajectory, are concretely presented in the snapshots of head perturbations in the aquifer. Our finite element modeling provides useful information for understanding the behaviors of diffusive pressure propagation in an aquifer with stratigraphical and/or structural heterogeneities, and for designing hydraulic tomography to enhance aquifer characterization.     

银纳米薄膜试片在博物馆藏展材料评估筛选中的应用

Oddy测试法是一种最为常用的评估材料是否适合博物馆文物储藏与展示的测试方法,其缺点在于采用活性低的块状金属试片,需要28天的测试周期,同时试片表面平整度以及人为主观因素会影响目测结果的准确性.本工作制备了银纳米薄膜试片替代Oddy测试法中块状金属试片,以半径10mm玻璃圆片为基质,银薄膜厚度约为200～220nm.实验结果表明,采用银纳米薄膜试片后,腐蚀现象在14d后可充分显现并分化,延长至28d时腐蚀现象基本无大变化,有效的缩短了测试周期.同时尝试结合数码图像采集技术,有利于进一步的腐蚀现象数据化分析研究工作,从而得到更加客观准确的测试结果.     

薄膜试片测试法试片图像采集分析系统

薄膜试片测试法是一种能够全面有效地对博物馆藏展材料进行评估筛选的测试方法,对其腐蚀现象进行图象采集及进行数据化分析能够得到更为客观准确的测试结果.本工作对应该测试法设计了专门图像采集的硬件装置,采用密闭光源和彩色工业摄像机,可以得到清晰的试片图像.软件系统将采集图像、打开原始图像、图像分割处理、材料分级评价等功能模块化,并根据具体功能设计实现了基本应用的可视化界面.实验表明,该系统能够快速、准确地对藏展材料对试片的腐蚀现象进行数据化分析,使藏展材料的评估分级由人工目测走向计算机视觉计算,具有快速、客观、误差小等特点.