我国西南喀斯特生态修复的十大问题与对策

西南喀斯特地区是美丽中国建设的重点和难点区域之一,其中包括土壤侵蚀、坡耕地比例、水资源污染、岩溶干旱、生态修复、协同碳汇、城市化生态效应、石漠化治理指标、生物多样性及可持续性评估等方面的问题。文章将喀斯特地区生态修复实践过程中积累的知识综合成土壤侵蚀、坡耕地比例、水资源污染、岩溶干旱、生态修复、协同碳汇、城市化生态效应、石漠化治理指标、生物多样性及可持续性评估等10个方面的问题和解决措施。它们有助于解释在喀斯特生态修复方面实现可持续性所面临的挑战,进而文章也指出了解决办法。它们构成了一套核心原则,可以指导科学家、政策制定者和实践者应对喀斯特生态修复工程中的可持续性挑战。     

乐山大佛基岩酸雨影响评价及防治对策

在酸雨的作用下,大佛砂岩的风化剥蚀作用很强烈,为定量研究酸雨对乐山大佛基岩的影响,实地采集了乐山大佛基岩及乐山酸雨样本,搜集了大量相关资料,进行了模拟酸雨试验。研究表明,乐山大佛早期的新鲜基岩,在长期的风化剥蚀作用下,由外到内形成了粉末层—硬壳层—风化层—新鲜基岩层,这一完整的表层层次结构。这种层次模式是由岩石表面逐渐递次向岩石内部发展的。通过模拟酸雨试验还发现,乐山大佛基岩,在最近30年酸雨的作用下,风化剥蚀作用强烈.,平均剥蚀速率在0.2克/小时·平方米左右,总计被剥蚀厚度约2厘米。提出了应更高度警惕酸雨对乐山大佛裸露基岩的破坏,进一步深化对乐山大佛裸露基岩保护的相应防治对策。     

A Multi Proxy Investigation of Moisture,Salt, and Weathering Dynamics on a Historic Urban Boundary Wall in Oxford,UK

ABSTRACT

Boundary walls are neglected but important parts of historic urban environments, and they are often prone to serious deterioration. Understanding moisture and salt dynamics within boundary walls can help infer the causes and dynamics of deterioration. This investigation investigates the patterns of moisture, salt, and deterioration on a 300 year old limestone boundary wall in Worcester College, Oxford. Multiple methods to assess moisture and salts within and across the wall (electrical resistivity tomography, handheld resistivity-based moisture meter, paper pulp poultices, scanning electron microscopy, inductively coupled plasma optical emission spectrometry, and ion chromatography of small scale sampling of deteriorated limestone) were used in conjunction with decay mapping of both sides of the wall. The salt weathering strongly correlates with severely weathered zones at the wall and salts, mainly sulfates, seem to be the main agent of decay processes. The combined results demonstrate that the environmental influences driving stone decay can differ on a very small scale even at a comparatively simple structure like a boundary wall, and that repairs can have adverse effects if the patterns of salt and moisture dynamics are not sufficiently known.     

Building stone and related weathering in the architecture of the ancient city of Naples

The survey of materials constituting the buildings of the ancient city centre of Naples and of their decay typologies was carried out. Reports were entered in a database which enabled us to draw two thematic maps in a digital format: one of materials and lithotypes, and one showing weathering. On this basis, quantitative evaluations of the lithotypes were carried out. The research pointed out that the use of different lithotypes was mainly as a result of their availability and/or ease of exploitation. Furthermore, the importance of the preservation of the quarrying sites was stressed, both for their historical and cultural interest and, above all, for possible forthcoming provisioning finalized to restorations. The analysis of the results, made on a geo-mineralogical basis, as well as the thematic maps, gives a basic tool which will be very useful to those professionals involved in preservation of cultural heritage.     

耐候钢焊接接头锈层稳定化大气曝晒加速试验

利用锈层稳定化处理的耐候钢焊接接头,进行了大气曝晒(喷淋)加速试验,结果证明:经表面复合处理剂处理后的Q450NQR1耐候钢,腐蚀率显著降低,不仅提高了耐蚀性,而且也提高了抗局部腐蚀能力。经表面复合处理剂处理的焊接接头与非焊接样的腐蚀试验结果没有差别,说明表面复合处理剂适用于焊接接头的锈层稳定化处理。     

Non-destructive Analysis and Deterioration Study of a Decorated Famille Rose Porcelain Bowl of Qianlong Reign from the Forbidden City

ABSTRACT

In August 2014, a pit containing more than 10000 porcelain shards was excavated in the southwestern area of the Palace Museum. Reign marks and other stylistic criteria dated the manufacture of these fragments from the reign of Hongwu in the Ming Dynasty (1368–98 CE) to the Guangxu reign in the Qing Dynasty (1875–1908 CE). A famille rose (fencai, 粉彩) bowl decorated with a red-ground peony pattern and having the reign mark of Qianlong (1736–96 CE) on the base was studied using several non-destructive analytical methods to determine the variation in overglaze compositions, the colorants, the application sequences, the thickness of the colored layers and the high-temperature porcelain glaze, and the identification of the surface weathering products that formed during burial. The methods include non-destructive X-ray fluorescence, Raman spectroscopy, optical stereomicroscopy, and laser confocal microscopy, as well as X-ray diffraction.     

边贡对王士禛诗歌创作的影响

边贡是＂前七子＂的代表人物之一,也是＂弘治四杰＂的中流砥柱。虽然其影响不足与李东阳、何景明相抗衡,诗学理论也不足与谢榛相左,其在有明一代也具有举足轻重的影响。他那沉稳飘逸的诗风取向对同乡后辈王士禛的诗歌尤其是他的神韵诗产生了重要的影响。从他对王士禛创作的影响中我们可以看到诗人的创作风貌如何被后代诗人继承发展的,而且可以看到明清诗歌之间的血肉联系。     

桂山岛地下水的地质条件及其开发利用

桂山岛断裂有东西、北东、南北、北北西及北西西向几组,虽规模不大,但有一定密度,在断裂旁侧,特别是上盘,存在较密集的节理裂隙带,增加了断层的透水性,形成带状裂隙水。本文提出了几种开采地下水方案,如横穿断裂开挖躺井、在构造带有利部位钻探、开挖大井或水塘截流泉水等。     

承德避暑山庄石质文物的风化腐蚀模拟实验

通过对承德避暑山庄石刻表面风化产物的监测数据的分析,发现对石刻构成破坏最为主要外因以水(降雨+毛细水)、可溶盐及融冻破坏这三种主要因素。选取与承德避暑山庄石刻材质相同的火山凝灰岩样品,模拟自然腐蚀中的风化因素,分别对不同编号样品进行可溶盐浸泡、盐雾实验和冻融实验,进行人为加速老化,通过对石材样块的腐蚀情况的深入考察,以期为后期的保护工作制定合理的计划。     

Measuring Weathering and Nanoparticle Coating Impact on Surface Roughness of Natural Stones

ABSTRACT

The surface texture of a stone represents a sensitive parameter in evaluating its conservation state. In monuments and sculptures, in fact, external agents continuously alter the appearance of stones, determining peculiar weathering patterns and modifying properties such as retention of water and particles, interaction with light, color, and finishing. The application of protective coatings also determines changes in surface appearance of a stone, usually evaluated and monitored by color change tests. Surface metrology methods offer the possibility to quantify these changes, evaluating the impact of external agents (natural, i.e. weathering, and artificially, i.e. protective coatings) on natural stones. In this research, we demonstrate the potential of surface areal measurements in describing the evolution of weathering processes and the effects of protective treatments on porous stone materials. The obtained results suggest that the extent of the modifications is related to the scale of observation (small- vs. large-scale undulations, i.e. roughness and waviness, respectively), with an overall increase of surface roughness as the weathering proceeds. Unexpectedly, coatings based on nanoparticle dispersions increase the topographic height parameters, due to the absence of a homogeneous film.