烧制温度对红砖物理力学性质的影响

在多年自然营力作用下,有些古建筑的砖体正遭受着严重的风化破坏,亟需修复和加固。为此,通过试验,研究烧制温度对红砖物理力学性质的影响,以期为古建筑修复和保护提供理论参考。利用模具手工制作边长为5 cm的立方体黏土砖。利用高温炉分别在700、800、900、1 000和1 100℃的温度下烧制成红砖。然后,测试不同烧制温度下红砖的块体密度、颗粒密度、开孔孔隙率、总孔隙率、常压吸水率、饱和吸水率、毛细吸水系数、纵波波速、孔径分布、单轴抗压强度。结果表明,烧制温度会影响物理力学性质,但物理力学性质并非随着烧制温度的增加而改善。烧制温度为1 100℃时砖的性能最优,烧制温度为800℃和900℃时砖的性能中等,烧制温度为700℃和1 000℃时砖的性能差。本文分析了烧制温度为1 000℃时红砖的物理力学性质差的原因。研究结果可为古建筑修复和保护提供理论参考。     

湘淮集团与19世纪60年代上海的崛起

19世纪60年代,是上海从"江南的上海"向"上海的江南"过渡的关键时期。这一时期,湘淮集团一方面通过解除太平军对上海围困,解决在此过程中产生的诸多社会问题,有效控制了上海的军政大权;另一方面通过采取系列的手段和措施,以处理日显复杂的上海中外关系,为上海的发展创造了一个相对安定和平的环境,从而成为了19世纪60年代上海崛起的一个重要因素。     

The Experimental Study of Palaeolithic Heat‐Treatment Technology: A Case from the Shuidonggou Rock Resources,North‐West China

The application of heat‐treatment technology on lithic raw materials is an important feature of early modern human behaviour. The evidence of heat‐treated stone artefacts discovered at Localities 2 and 12 of the Shuidonggou Late Palaeolithic site, North‐West China, provides an important example for studying this technology among ancient humans in Asia during the Late Palaeolithic. The mechanism and effects of heat treatment on raw materials and the role of this technology in producing stone tools were studied by means of a simulation experiment and related analytical methods. These facilitated an in‐depth analysis of the heat‐treatment activities of the Shuidonggou occupants and their implications for cognitive ability and survival strategies of human populations at that time.     

Guidelines for On-Site Assessment of Historic Timber Structures

In the scope of European Cooperation in Science and Technology–Wood Science for Conservation of Cultural Heritage (COST IE0601–WoodCultHer) (available at http://www.woodculther.org) it was agreed to produce Guidelines for the Assessment of Historic Timber Structures, covering the principles and possible approaches for the safety assessment of old timber structures of historical relevance that could be used as the basis for possible European Standards, as discussed with CEN/TC346 (Conservation of Cultural Heritage).

This approach was targeted at all those concerned with the conservation of heritage buildings. These guidelines should also help decision-making regarding the need for immediate safety measures. The aim is to guarantee that inspection and assessment measures provide the necessary data for historical analysis, structural safety assessment, and planning of intervention works, while having minimal impact on the building fabric (the original materials, structural systems, and techniques).This article provides information on the criteria to be used in the assessment of load-bearing timber structures in heritage buildings. It covers the preliminary assessment (desk survey, preliminary visual survey, measured survey, structural analysis, and preliminary report), as well as the detailed survey of timbers (with a special emphasis on visual strength grading on site) and carpentry joints. The subsequent diagnostic report and the detailed design of repairs are outside its scope.     

SEM,EPR and ToF-SIMS analyses applied to unravel the technology employed for pottery-making by pre-colonial Indian tribes from Pantanal,Brazil

The present work aims at elucidating the technology applied in the fabrication of ceramic objects by the ancient ceramists that inhabited the western border of Pantanal, Mato-Grosso do Sul, with the help of a multidisciplinary approach making use of chemical and physical methods of analysis. The potshards under study show the presence of different types of additives, as determined by scanning electron microscopy (SEM) and time of flight secondary ion mass spectrometry (ToF-SIMS). The dispersion of the additives within the ceramic matrix was also addressed by SEM, which shed light on the mounting technique used by the potters to assemble the ceramic vessels. Moreover, the tensile strength conferred to the pottery by the use of a specific type of additive was evaluated by applying a mechanical test. These results were correlated with the firing temperature of the potshards, determined by means of electron paramagnetic resonance (EPR).     

上下椽头尾搭接的木构古建筑受力性能的简化计算方法研究

古建筑木结构主要分为抬梁木构体系和穿斗木构体系,其结构布置与连接节点明显不同于现代木结构。为了进一步提高古建筑木结构的结构计算和结构安全评估的工程实用性,对常见木椽的受力性能简化算法、常见拼合檩条的受力性能简化算法、三架梁和五架梁受力性能的简化算法进行研究,并基于动力特性分析,初步提出古建筑木结构典型构架体系在进深方向和面阔方向结构基本自振周期的近似计算模型。研究成果可为古建筑木结构的结构性能计算、结构安全评估以及加固修缮设计提供依据和参考。     

The evolution of strength,elasticity and rupture behaviour of birch tar made with ‘double-pot’ techniques during tar cooking

Birch tar was the first adhesive produced by humans. Its study has consequences for our understanding of human evolution and the development of specialised craftsmanship. One of the better-documented birch tar making methods is the ‘double-pot’ technique, where two containers are used, one containing bark, the other collecting the tar. Birch tar made with double-pots has low viscosity and bad adhesive properties. To obtain a usable adhesive, it must be reduced in volume by cooking. We investigate the evolution of tar’s mechanical properties during cooking. We use lap-shear tests to investigate strength, stiffness and failure behaviour. We found that tar must be cooked for 90 min to acquire adhesive properties. When cooked for longer, strength and stiffness increase over a 30 min lasting time span. Cooking for even longer, beyond this 30 min window, produced a substance that could no longer be used as an adhesive. The implications are that tar cooking requires a high level of skill because specific signs indicating the desired properties must be recognised during the process. Tar cooking constitutes a supplementary investment in time and resources and appears to be associated with a certain degree of risk.     

室外金属文物表面保护材料的探讨

根据物保护科学技术的特殊要求,调查了各种涂料的性能以及使用效果,分别选择有代表性的有机硅类涂料、聚氨酯类、硝基清漆和丙烯酸类涂料样品重新试验验证。按涂料行业的标准检验方法,对涂护材料的弯曲强度、冲击力、硬度及附着力指标进行测试检验,从中选出最佳室外金属物表面保护材料。经过试验验证所得结果与现实应用相一致。     

新型防腐防霉剂在纺织品防腐中的应用（Ⅱ）

试验了新型防腐防霉剂霉敌在棉、毛、丝、麻4类纺织品防霉中的应用。上述4类织品2年老化后测定结果表明,霉敌具有良好的防霉能力,防霉样品的拉伸强力和撕裂强力比对照样品均有提高,且织品颜色未发生改变。     

The mechanical properties of macrolithic artifacts: a methodological background for functional analysis

Natural, technical and social factors led to the use of a wide range of rocks for the production of macrolithic artifacts during the later prehistory. In the case of some artifact types, such as the grinding stones, rocks with very different petrographic qualities appear. Analysis of the material behavior, as developed by material sciences, provides a tool which allows the translation of these petrographic characteristics into mechanical properties. Experiments with a group of rocks subjected to different forms of abrasion in industrial machines allow an evaluation of the adjustment between the mechanical properties of the rock and the functions for which they were chosen by prehistoric societies. Finally, the understanding of the mechanical properties of the raw materials together with their forms of exploitation, distribution and use allows the designation of social and economic meaning to the production systems linked to the macrolithic tools.