丁二酮肟修饰碳糊电极的制备及对Cu（Ⅱ）的测定

提出用丁二酮肟修饰碳糊电极的制备及对Cu（Ⅱ）的测定.以铂丝电极为对电极,Ag/AgCl电极为参比电极,在pH=3.2的邻苯二甲酸氢钾—盐酸缓冲溶液中通过在-1.0V电位下富集后,在-1.0V～＋0.6V电位范围内作线性扫描溶出伏安法测定,峰电流与Cu（Ⅱ）浓度在4.0×10^-6～5.0×10^-5mol/L范围内呈良好线性关系,当富集300s时检测限为1.0×10^-9mol/L,且大多数阳离子不干扰测试结果.     

催化动力学光度法测定痕量铜的研究

本文发现了在氨性介质中,痕量铜催化过氧化氢氧化溴甲酚紫褪色的指示反应.研究了催化褪色反应的最佳条件和动力学参数,建立了测定痕量铜的新方法,方法的最低检测限为2.75×10~(-9)g/ml,测定范围0.2—1.0μgCu(Ⅱ)/26ml,用于测定人发中的Cu(Ⅱ),获得了满意的结果.     

Regional Distribution of Copper,Zinc and Iron in Brain of Wistar Rat Model for Non-Wilsonian Brain Copper Toxicosis

In previous studies, we have reported first in vivo evidence of copper deposition in the choroid plexus, cognitive impairments, astrocytes swelling (Alzheimer type II cells) and astrogliosis (increase in number of astrocytes), and degenerated neurons coupled with significant increase in the hippocampus copper and zinc content in copper-intoxicated Wistar rats. Nonetheless, hippocampus iron levels were not affected by chronic copper-intoxication. Notwithstanding information on distribution of copper, zinc and iron status in different regions of brain due to chronic copper exposure remains fragmentary. In continuation with our previous study, the aim of this study was to investigate the effects of intraperitoneally injected copper lactate (0.15 mg Cu/100 g body weight) daily for 90 days on copper, zinc and iron levels in different regions of the brain using atomic absorption spectrophotometry. Copper-intoxicated group showed significantly increased cortex, cerebellum and striatum copper content (76, 46.8 and 80.7 % increase, respectively) compared to control group. However, non-significant changes were observed for the zinc and iron content in cortex, cerebellum and striatum due to chronic copper exposure. In conclusion, the current study demonstrates that chronic copper toxicity causes differential copper buildup in cortex, cerebellum and striatum region of central nervous system of male Wistar rats; signifying the critical requirement to discretely evaluate the effect of copper neurotoxicity in different brain regions, and ensuing neuropathological and cognitive dysfunctions.     

秩序的标记与事件无关--论李洱小说的叙述时间

李洱是一个对细节极为敏感的作家，对细节的张扬造就了李洱小说独特的时间景观。论文通过文本细读，从不需要向故事时间复原的碎片时间、叙述时间上强烈的节奏感以及文本所呈现出来的涡卷图案的叙述线条三个方面，论证了时间在李洱小说中所具有的修辞意义。     

2-(2-咪唑偶氮)-5-二乙氨基酚与铜显色反应的研究

研究了新显色剂2-(2-咪唑偶氮)-5-二乙氨基酚(简称IZAPN)与铜显色反应的条件,结果表明,在pH5.0的HAc-NaAc介质中,试剂与铜形成紫红色的络合物,络合物的λmax为547nm,试剂的λmax为477nm,对比度△λ为70nm,络合比Cu~(2 ):R为1:2,摩尔吸光系数为2.22×10~4L·mol~(-1)·cm~)-1_,Cu~(2 )在0～0.8mg/L范围内服从比耳定律,该方法直接测定铸造镁合金和铝合金中微量的铜,结果满意.     

非物质文化遗产保护传承机制探析——以贵州镇宁布依族铜鼓十二调为例

民族文化是维系一个民族过去、现在与未来重要的精神纽带,是一个民族区别其他民族独特文化资质的表征,更是加强民族社会安定团结、鼓舞民族意志的重要载体。贵州镇宁布依族铜鼓十二调作为国家级非物质文化遗产,在新的社会环境下如何使其更长远持续的传承和保护,对其传承机制进行探索研究就显得非常有必要。     

Degradation of Emerald green in oil paint and its contribution to the rapid change in colour of the Descente des vaches (1834–1835) painted by Théodore Rousseau

Abstract

Descente des vaches (1836) by Théodore Rousseau in the Mesdag Collection in The Hague is barely readable and its paint layers are in poor condition. The surface of the painting is strongly deformed and cracked, the whole painting has darkened and especially the greens have lost all or most of their colour resulting in brown passages. Large passages of the painting that were painted with multiple thick and medium-rich layers have darkened dramatically. This paper proposes that the degradation of Emerald green (Cu(C₂H₃O₂)₂·3Cu(AsO₂)₂, copperacetoarsenite) – the main green pigment used in this painting – is a significant factor in the cause of the darkening. Electron backscatter images reveal that the Emerald green particles are shown different degrees of degradation: from partially to completely disintegrated. Elemental maps show that arsenic is distributed throughout the paint cross section, with relatively higher concentrations around iron- and aluminium-containing particles, and in the varnish layer. Imaging-Fourier-transform infrared microscopy detects copper soaps in the degraded Emerald green-containing layers. Analytical data from four paint cross sections strongly suggest that Emerald green reacts with free fatty acids derived from the binding medium forming copper soaps and mobile arsenic-based species. Chemical laboratory experiments fully support this hypothesis. Emerald green and palmitic acid in chloroform form copper palmitate and arsenic trioxide (arsenolite, cubic) under room temperature and normal light conditions. The degradation of Emerald green particles in Descente des vaches has resulted in a loss of light-reflecting surfaces and in newly formed compounds in the paint, both contribute to the colour change from green to brown.     

Real-time monitoring of indoor air corrosivity in cultural heritage institutions with metallic electrical resistance sensors

Abstract

A system for continuous monitoring of atmospheric corrosivity has been developed. An electronic unit measures and records changes in the electrical resistance of a thin metal track applied on an insulating substrate. If the metal corrodes, the effective cross sectional area of the track decreases and the electrical resistance increases. Sensors made of silver, copper, iron/steel, zinc, lead, tin, aluminium, bronze, and brass at thicknesses from 50 nm to 250 µm were tailored for environments with different corrosivities. The developed technology proved capable of providing high sensitivity, allowing for real-time corrosion monitoring even in low-corrosive indoor cultural heritage facilities. Laboratory tests showed good reproducibility with the standard deviation of parallel measurements at less than ±20% for metals which corrode uniformly in the tested environments. Several examples selected from a broad testing programme in partner museums, libraries, and other institutions show successful applications of the logger system for characterization of air quality control in indoor locations, during transport and in temporary exhibitions; assessment of new buildings and storage facilities; and fundamental studies of optimal conservation and storage procedures. A first outline of a classification system for lead, which is particularly sensitive to the presence of carboxylic acids, is given. The technique has a large potential as an independent method for monitoring air quality in facilities displaying and storing valuable objects of cultural heritage.