Study of the stability of a series of synthetic colorants applied with styrene-acrylic copolymer, widely used in contemporary paintings, concerning the effects of accelerated ageing

This study examines the materials of a contemporary pictorial artwork, belonging to the Macedonian Museum of Contemporary Art in Thessaloniki (Greece), and needing conservation. The combined use of micro-FTIR and micro-Raman spectroscopy allowed the identification of almost all painting materials. Moreover, the stability of a series of synthetic pigments towards accelerated ageing is investigated in applications using the contemporary binding medium styrene-acrylic copolymer. The pigments in question are: Hansa yellow PY3 and PY74, quinacridone PV19 and PR122, naphthol AS PR112, phthalocyanine green PG7 and blue PB15, dioxazine PV37, van Dyck brown PBk11, ivory black PBk9, and titanium dioxide PW6. The organic pigments were applied alone or mixed with titanium dioxide, in rutile form or as a mixture of rutile/anatase. The experimental swatches were subjected to ageing tests, and subsequently studied as to colour changes by means of colorimetric measurements, and as to the molecular structure differentiations by infrared spectroscopy in reflectance mode. The ageing tests included exposure to high temperature and humidity (90 °C, 60% RH) and to ultraviolet radiation (350 nm, 30 °C and 50% RH, with a substantial temperature increase at 90 °C for 3 days). The greater colour difference is caused by high temperature and humidity, whereas paint layers containing TiO₂, and especially the mixture of the forms rutile/anatase, prove very susceptible to ultraviolet radiation, demonstrating a significant colour difference and extended molecular changes.     

SAR原始数据压缩的自适应比特分配BAQ算法

针对SAR原始数据压缩,在传统BAQ算法基础上,提出一种分块量化比特率可变的BAQ算法,在保持各分块平均比特率固定的前提下,针对不同的数据分块自适应选择量化比特率。与已有的改进型BAQ算法相比,比特率选择机制基于分块数据的信号功率大小,不需要成像区域的先验知识。新方法能够明显提高数据量化信噪比并降低SAR复图像相位误差,而运算复杂度增加很小,并可以实现分数比特率,适应于不同通信带宽的数据传输需要,增加了SAR原始数据实时传输的灵活性。     

有机合成反应选择性及其控制策略

有机合成是化学研究领域中最具有魅力的。结构复杂、性质多元、应用广泛的有机物及其合成方法学,让人赞叹与探求。文章用科学方法论总结了有机合成中的化学选择性、区域选择性和立体选择性的规律及其热力学和动力学控制策略,提出了综合利用其控制原理解释或预测竞争性反应产物的基本方法。     

论体育院校学生综合素质的培养

针对体育院校学生素质教育中存在的人文精神与科学素养、通识教育与专业教育、体育科学与教育科学、体育理论与实践如何有机结合等问题,提出了体育院校学生综合素质培养的几种手段和方法。     

山东省青少年足球运动现状的调查与分析

以参加 2 0 0 0年山东省青少年足球锦标赛的运动员为研究对象 ,对当前我省从事足球运动的青少年年龄结构、参赛人数和比赛成绩等方面进行了调查分析 ,认为我省青少年足球运动员年龄结构较理想 ,梯队建设较好 ,但各地市之间的普及和发展有失平衡 ,尖子运动员产出率偏低 ,赛场风气有待净化 ,运动员的综合素质有待提高     

La Medusa by Caravaggio: characterisation of the painting technique and evaluation of the state of conservation

The oil painting “La Medusa” executed by Caravaggio at the end of the XVI century on a wooden shield, was investigated by integrated physical–chemical and analytical methodologies in order to obtain scientific data capable of elucidating the state of conservation and the painting technique. Optical (OM) and electronic (SEM-EDS) microscopy, micro-FT-IR spectroscopy, gas chromatography–mass spectrometry (GC–MS) and pyrolysis GC–MS were applied on two microfragments and some organic samples obtained by solvent extraction using the swab cleaning technique. The obtained results indicated that Caravaggio probably reused an old shield as a previous gypsum preparation layer has been detected under the original painting layers. He used white lead, natural earths, verdigris and lead–tin yellow type I mixed with drying oils to paint. The considerable amount of amorphous particles of copper chlorides found in the green pigment verdigris suggests that it could have been produced according to the ancient recipe of verde salsum described by Theophilus. Mordant gilding has been identified on the upper part of the shield that can be related to an abandoned experiment to give the painting a mirror-like reflecting effect. Three different varnishes layers have been detected above the painted surface. The original and restoration varnishes have been identified and they contain a mixture of drying oil, mastic and turpentine and some beeswax. Cleaning tests, performed with different organic solvents, suggest the use of isopropyl alcohol as cleaning agent because it is less efficient in comparison to others solvents; thus it ensures a careful and controlled removal of the varnishes.     

杭州市PM10中有机碳和元素碳变化特征

2001年2月至2002年4月在杭州5个空气质量国控点采集176组PM10样品,分析有机碳（OC）和元素碳（EC）含量,并采用TEOM法同步监测PM10质量浓度,其中在卧龙桥国控点同时测PM2.5质量浓度。全市PM10年日均浓度为119.2mg•m-3。PM2.5年日均浓度为68mg•m-3。PM2.5与PM10质量浓度呈显著的线性关系。PM2.5/ PM10日浓度比值范围在0.31-0.95间变化,平均比值为0.62。OC和EC浓度分别为20.4 mg•m-3和4.0 mg•m-3,其相关性不好表明碳的来源复杂。二次有机碳（SOC）分别占各季OC的 37.1%,45.8%,58.0%,44.7%,表明杭州空气中存在一定的二次有机污染。     

融合深度学习和链路预测的细粒度技术预测研究——以合成生物技术为例

[目的/意义]面向专利文本进行更细粒度的技术实体识别和技术预测,利于更详细地把握专利技术布局与趋势。[方法/过程]首先利用深度学习方法自动识别专利技术术语类实体,通过实验对比多组深度学习算法的优劣。其次,提出新的半监督标注和自定义标注方案,提高人工标注效率。最后,执行训练得到的最优模型,结合链路预测方法,对合成生物技术进行细粒度的技术预测。[结果/结论]实证结果表明RoBERTa-BiLSTM-CRF模型更适用于语义复杂的专利技术实体识别,F1值可达到86.8%,技术识别结果比传统IPC分析方法更精细。同时,细粒度的技术预测结果表明,合成生物学的合成方法在不断改进创新,合成物研究向合成燃料发展。     

模糊综合评价方法在广告效果测定中的运用

广告效果构成因素的复杂性决定了广告效果评价的模糊性.建立广告效果模糊综合评价定量分析模型的步骤包括建立广告效果模糊综合评价的因素集、评价集、权重集、评价矩阵和求得评价结果等内容.     

我国综合性大型体育赛事场馆设施建设的双重困境

采用文献资料法和数理统计法等，对我国综合性大型体育赛事场馆设施建设的现状进行分析。认为：市场失灵和政府失灵是导致综合性大型体育赛事场馆设施建设困境的主要原因，并就其表现形式和原因进行论述。提出明确政府职能、加大政府投入、建立科学决策机制、提高场馆设施建设决策的科学性、政府与市场合作、实现优势互补、弥补各自缺陷以及实施场馆设施建设的民营化战略发展对策。