赤铁矿及孔雀石对桐油和大漆老化性能的影响

本文以在古代壁画中广泛使用的大漆和桐油粘合剂为分析研究对象,以赤铁矿和孔雀石为颜料,采用傅立叶变换红外光谱（FT-IR）和示差扫描量热（DSC）分析方法,研究了赤铁矿和孔雀石两种颜料对大漆和桐油老化性能的影响。研究结果表明,桐油比大漆的耐老化性能好,赤铁矿和孔雀石加快了桐油老化速度,而且赤铁矿的催化老化效果更突出。赤铁矿加快了大漆的老化,但孔雀石对大漆老化的影响不明显。     

Quantifying secondary migration efficiencies

Exploration success relies on properly risking the hydrocarbon system relevant for each prospect. Accurate risking of secondary migration efficiencies has been difficult due to lack of simple procedures that relate rock properties such as permeability and entry pressures to migration velocities, oil stringer heights and saturations. In order to achieve improved estimates of charge probabilities, equations for the secondary migration process are formulated based upon the Darcy flow and buoyancy conditions. An analytical solution of the formulated equations is shown, making it possible to construct charts for efficiently assessing the column height of secondary migration hydrocarbon stringers. The average oil (hydrocarbon) saturation of the migrating stringer can be computed, making it easy to compute the permeability related, secondary migration losses. Inputs to the chart are hydrocarbon flow‐rates and flow‐path width, hydrocarbon viscosity and density, carrier bed dip, permeability and entry pressures. Outputs are stringer heights, hydrocarbon saturation, relative permeability, migration velocities and migration losses. A procedure for including the new equations into existing basin scale fluid flow simulators is outlined and a Java applet for calculating the properties is described. The Java applet is useful for sensitivity studies, and can also be used to test results from basin simulators with the new migration efficiency equations. The analytical solution suggests that many published methods for calculating hydrocarbon migration in fluid flow simulators will over‐estimate hydrocarbon saturations and therefore losses. Calculated migration velocities will also be too low.     

Investigating shellfish deposition and landscape history at the Natia Beach site,Fiji

The relationship between environmental variation and subsistence practices is a central point of discussion in much Oceanic archaeology. While human predation can significantly reduce prey populations, environmental variation also contributes to reductions in prey abundance, possibly leading to increased human competition and resource scarcity. At the Natia Beach site, Nacula Island, Fiji, geoarchaeological evidence suggests that coastal progradation began soon after initial occupation of the coastal plain. Additionally, at approximately 650 BP a marked increase in clay and silt deposition occurred. Changes in coastal geomorphology may be explained by landscape response to regional Mid-Holocene sea level fall combined with human induced soil erosion due to upland settlement. Smaller scale environmental changes associated with climate variability may have also played a role. Additionally, landscape change appears to have had a measurable impact on local nearshore mollusks that are sensitive to high levels of water turbidity. Minor evidence of human exploitation is observable in this shellfish assemblage, although changes in predation pressure may have allowed shellfish populations to recover. Increased ceramic diversity and fortified settlements also appear at approximately 650 BP on Nacula and other parts of Fiji. The suite of changes at Natia may be explained by processes of regional and local environmental changes, and human adaptation in terms of subsistence, spatial organization, and competition.     

Petroleum type determination through homogenization temperature and vapour volume fraction measurements in fluid inclusions

Physical parameters of petroleum‐bearing fluid inclusions such as bulk density (ρ), molar volume (V_m), vapour volume fraction (?_vap) and homogenization temperature (T_h) are essential information to model petroleum composition (x) in inclusions and to reconstruct palaeotemperature and palaeopressure of trapping. For the main petroleum types contained in a fluid inclusion, we can follow how ?_vap and T_h are simultaneously influenced by a change of bulk density in a ?_vap versus T_h projection. We have correlated T_h and ?_vap for different petroleum compositions for a large range of bulk density values. However, postentrapment events under new pressure (P) and temperature (T) conditions can greatly modify the initial fingerprints of physical conditions and chemical composition of fluid inclusions. Re‐equilibration is frequent, especially in the case of fragile minerals. Stretching and leakage phenomenon have been simulated using the Petroleum Inclusion Thermodynamics (pit ) software, from virtual petroleum inclusions with known hydrocarbon composition. The aim of these simulations is to understand how ?_vap and T_h evolve with these re‐equilibration phenomena, with respect to the oil composition. Results of stretching simulations show a characteristic increase of T_h and ?_vap along correlation curves, with the curve shape dependent on petroleum composition. Leakage simulations show an increase of T_h and a smaller increase or even a decrease in ?_vap. Consequently, the better preserved inclusions in a given population can be presumed to be those that have the lowest T_h. Applications of T_h and ?_vap measurements of natural inclusions in calcite and in quartz showed that the fragility of the host mineral is a key factor allowing the recording of post‐entrapment events. Inclusions that have stretched or leaked are identified and the best preserved inclusions selected for evaluation of P–T–x trapping conditions. Moreover, petroleum types trapped in inclusions can be identified from ?_vap and T_h measurements without compositional modelling.     

Thinking without the ‘circle’: Marine plastic and global ethics

Marine plastic has received significant attention as a spectacle of consumer waste and ecosystemic fragility, but there has been little discussion of its ethical implications. This essay argues that marine plastic poses a direct challenge to the basic frameworks of global ethics. These frameworks are dominated by the image of the ‘circle’, an abstract boundary intended to separate ‘humanity’ from the rest of the universe and insulate it against harm. However, this article argues that marine plastic undermines the ‘circle’ in two ways. First, it embodies conditions of ‘hyper-relationality’, including entanglement and the properties of toxicity, that penetrate the boundaries of ‘the circle’. Second, it exerts ‘forcefulness’, but at scales that radically exceed the dominant spatio-temporal dimensions of ‘the circle’. By virtue of these features, marine plastic thoroughly penetrates the boundaries of ‘the circle’, making it impossible to expel harm beyond its boundaries. Although this essay focuses on marine plastic, its core argument can also be fruitfully applied to other phenomena that share similar material, scalar, spatio-temporal and relational features (for instance, atmospheric particulate, nuclear waste and nitrate pollution). The essay concludes by exploring the alternative ethical possibilities that marine plastic and similar phenomena prompt: in particular, a responsive ethos based on a sense of shared vulnerability and exposure.     

Russia’s energy relations with China: passing the strategic threshold?

This article examines Russian energy policies toward China over the past decade as reluctant engagement changed into a priority energy partnership. From 2008 to 2016 Russian and Chinese companies signed several major oil and gas agreements, a period in which Moscow reassessed China as a future energy consumer and lifted bilateral cooperation to a new level. The article utilizes the strategic partnership concept as an analytical framework and finds traditional realist concepts and hedging inadequate for this particular case. The study illuminates Russian geopolitical considerations and acceptance of vulnerability, which combined make long-term Russian energy policies more China dependent. Officially, Russia seeks diversification among Asian energy buyers, but its focus has increasingly been on China. Western sanctions imposed in 2014 for Russia’s role in Ukraine accelerated this trend. Moscow’s energy policies toward Beijing with its pipelines and long-term agreements are permanent arrangements that resemble strategic partnership policies. China is eager to increase energy relations with Russian companies, but Beijing also ensures that it does not become too dependent on one supplier. Russian concern over its increased dependence on China in the East is deemed secondary to expanding Russia’s customer base beyond the still-dominant European market.     

安徽博物院所藏7幅潘玉良油画矿物色料的组成分析

油画具有色料种类繁多、同一色系的颜料多样及对环境比较敏感等特性,加上颜料自身的风化作用,仅凭肉眼难以分辨。在修复性保护工作之前,对需要补色、补底处原色料的鉴定是一项基础性的工作,以便为修复时色料的选择提供依据。为此,本研究运用X射线衍射(XRD)、X射线荧光(XRF)等方法对7幅安徽博物院收藏的待修复的潘玉良油画矿物色料进行了物相及成分分析,讨论了补色修复时色料选择应注意的问题,以避免因色料粉之间不兼容(起化学反应)而对画作造成的二次伤害。     

宁波“小白礁I号”清代木质沉船中硫铁化合物脱除技术研究

近年来的分析与研究表明,海洋出水沉船的木材中普遍存在大量的以Fe S2和Fe S为代表的硫铁化合物难溶盐,它们在空气中和一定湿度条件下,会氧化生成硫酸,使木材纤维素发生快速降解,从而对木船造成毁灭性的破坏。目前,硫铁化合物的脱除仍然是世界性难题,很多国家发现的木质沉船都面临这方面的困扰。为此,本研究以宁波象山"小白礁I号"清代沉船遗址出水的船体木材构件为研究对象,研发了金属络合剂与氧化剂复配材料EDTAHO,开展了海洋出水木材中沉积的二硫化亚铁的去除技术初步研究,取得了良好的保护效果。本研究结果可为后续脱水定型和加固修复打下良好的基础,有利于海洋出水木质船体的长期保存。     

Antifungal activity of some plant extracts and essential oils against fungi-infested organic archaeological artefacts

The determination of the antifungal activities of nine kinds of powdered plant extracts and five essential oils was studied in vitro against four of the most common fungal species (Aspergillus flavus, A. versicolor, Penicillium sp. and P. purpurogenum), which were isolated from different organic materials from archaeological artefacts such as papyrus and linen. The essential oils showed greater efficacy than the powdered plant extracts, where thyme and lemongrass oils were the most potent. Also, the minimum inhibitory concentration and minimum fungicidal concentration of these oils were determined. Furthermore, their chemical components were identified using gas chromatography-mass spectrometry (GC-MS) analysis. In vivo, studies were performed using biodeteriorated samples for applying treatment, in which the microbiological test revealed that both oils can eradicate both tested fungi completely after exposure time, ranging from two weeks for papyrus samples to 14 weeks for linen. A scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and colorimeter were used to assess the treatment process, leading to the final results, which suggest that the essential oils could be useful sources of fungicidal preparations for the disinfection of biodeteriorated linen and papyrus artefacts. Nevertheless, further studies are strongly recommended to introduce these sources into practical use in preventive conservation.     

South African palaeoenvironments during marine oxygen isotope stage 4: a context for the Howiesons Poort and Still Bay industries

Spanning the period from ∼74–58 ka, and being broadly coeval with marine oxygen isotope stage 4 (MIS 4), the Still Bay and Howiesons Poort industries represent important phases in the development of the material culture of early modern humans. How and why these industries occurred when they did, however, remain matters for speculation. A key element of this debate has been the question of what role environmental change during the early stages of the last glacial period may have had on influencing human activity. Unfortunately, well-dated palaeoenvironmental evidence from this period is limited, and the debate has, out of necessity, been driven by the application of conceptual models of environmental change, many of which associate colder and warmer global climates with increased aridity and humidity respectively. In this paper, the regional marine and terrestrial evidence is synthesised to create an evidence-based palaeoenvironmental context. Based on the information available to date, it appears that rather than being characterised by dry conditions, MIS 4 was a period of relatively cool, moist climates, the ubiquity of which transcends the modern regional climate boundaries. It is suggested that orbital parameters at this time created greater interaction between tropical and temperate circulation systems, bringing more moisture to the subcontinent. These findings highlight the distinct nature of southern African climate systems, and caution against the application extra-regional conceptual models or inferring linear relationships with polar records.