一种油画颜料层裂纹的修复技术分析

油画颜料层裂纹是一种常见的病害类型,严重的裂纹会影响作品的视觉效果。裂纹修复所采取的措施应以缓解病害,延续寿命为目标,避免不当修复对其文物价值的改变。本研究通过红外光谱和便携式X荧光能谱分析,初步确定了裂纹产生的原因与材料技法和机械作用力有关,长期的温湿度波动则是最终形成老化裂纹的重要因素。对两类常见的裂纹加固方法比较后得出结论,色蜡改变了原画的光泽度和肌理层,动物胶调碳酸钙更适宜作为裂纹的填补材料。观察修复后的油画保存状况,发现经过修复的颜料层仍存在继续劣化的风险,必须维持保存环境的相对稳定,方可延长修复周期。     

Aggregation of Sampling Units: An Analytical Solution to Predict Variance

Geographical variables generally show spatially structured patterns corresponding to intrinsic characteristics of the environment. The size of the sampling unit has a critical effect on our perception of phenomena and is closely related to the variance and correlation structure of the data. Geostatistical theory uses analytical relationships for change of support (change of sampling unit size), allowing prediction of the variance and autocorrelation structure that would be observed if a survey was conducted using different sampling unit sizes. To check the geostatistical predictions, we use a test case about tree density in the tropical rain forest of the Pasoh Reserve, Malaysia. This data set contains exhaustive information about individual tree locations, so it allows us to simulate and compare various sampling designs. The original data set was reorganized to compute tree densities for 5 times 5-, 10 times 10-, and 20 times 20-meter quadrat sizes. Based upon the 5 times 5-meter data set, the spatial structure is modeled using a nugget effect (white noise) plus an exponential model. The change of support relationships, using within-quadrat variances inferred from the variogram model, predict the spatial autocorrelation structure and new variances corresponding to 10 times 10-meter and 20 times 20-meter quadrats. The theoretical and empirical results agreed closely, whereas neglecting the autocorrelation structure would have led to largely underestimating the variance. As the quadrat size increases, the range of autocorrelation increases, while the variance and the proportion of noise in the data decrease.     

The naming of orphans in France during World War One: A study of a nationwide cohort of pupilles de la Nation

The investigation of a simple behavior, child naming, can provide insights into the varying reactions of families confronted by the extraordinary war losses of the First World War. The current study analyses names given in a large cohort of French orphans born 1914–1916, constructed thanks to the linkage of civil registers with a nationwide database of soldiers who died during the War. It shows that a prenatal loss of father was associated with a strong increase in father's name transmission. The phenomenon was twice as intense in officers' offspring. Regression analysis suggests the precise timing of the father's death controlled this change in naming behavior: father's name transmission was at a maximum when the father died at the very beginning of pregnancy.