安定战略与南唐方镇体制的崩解

南唐方镇在许多方面都发生了重要变化,这些变化引发了方镇体制军事特质的丧失,因此南唐方镇的体制实际上已不再是原先的军政体制,而是一种新的民政体制。决定南唐方镇体制崩解的根本因素是安定战略。五代十国时期是一个特别值得重视的在政治体制方面发生变化的关键时期。     

西安新城市贫困空间固化及其治理研究——基于空间正义视角

新城市贫困空间固化及其治理研究,对破解城市发展不平衡不充分,促进城市社会公平公正具有重要理论和现实意义。基于西安市街道尺度问卷调查数据,采用贫困综合指数和构建空间固贫指数,在GIS技术支持下,对西安新城市贫困空间时空演化和固化趋势进行研究,并以空间正义为视角,提出西安新城市贫困空间固化治理方案。结果表明：①研究期内,西安新城市贫困程度不断减轻,贫困空间分布异质性明显,贫困空间演化整体上由放射状嵌套分布向圈层分布转变;②西安新城市贫困空间固化正在形成,空间固贫指数较高街道集中在内城衰退区,城市边缘失地农民聚居区、流动人口聚居区和遗址保护区;③西安新城市贫困空间固化治理要以空间正义思想为指引,在弘扬价值正义、制度正义和政策正义基础上,构建空间正义“起点-过程-结果”三位一体保障体系,确保城市空间生产公平公正。     

英国与中国的法币平准基金

英国对中国平准基金态度的演变 ,也是英国在远东与日本矛盾逐步激化、对华政策逐步趋于积极的过程。 1 93 5年中国实行法币政策时 ,英国没有加入中国平准基金。 1 93 7年中日战争爆发后 ,英国对该问题仍持消极态度。随着远东局势的演变 ,1 93 9年英国政府为英商银行加入中国平准基金提供担保 ,1 940年同意英商银行加入乙种平准基金 ,1 941年英国财政部直接供款加入中英美联合平准基金。 1 945年中英美平准基金的解散 ,则标志着英国在中国货币金融领域影响的终结     

Russian Agriculture During Putin's First Term and Beyond

An American specialist on Russian agriculture surveys developments during Putin's first term in office, as well as the challenges that loom for the future. The focus is on how economic growth more broadly, and agrarian reform policy more specifically, have led to increasing agricultural output and improved financial stability of farms, with emphasis on the large-farm sector (former state and collective farms). Among the at least partially successful stabilization measures described in some detail are development of reliable sources of farm credit, debt restructuring and cancellation, greater fulfillment of state budget obligations, state intervention in grain markets, and trade protectionism. The paper also assesses the agenda for increasing Russian agriculture's global competitiveness in Putin's second term. Journal of Economic Literature, Classification Numbers: F13, O18, Q10. 3 tables, 61 references.     

Unstabilized and stabilized compressed earth blocks with partial incorporation of recycled aggregates

This article aims to characterize the physical, mechanical, and water-resistant behavior of unstabilized and stabilized compressed earth blocks (CEB) produced with partial incorporation of recycled fine aggregates from construction debris. The objective was to produce an alternative-earth construction material with lower embodied energy. To this end, different types of common CEB were covered, namely: unstabilized CEB; stabilized CEB with 8% cement; stabilized CEB with 4% cement and 4% lime. CEB were characterized in terms of density, thermal conductivity, compressive and tensile strength, water absorption, permeability, and resistance to water erosion from drip and spray tests. The influence of moisture content was also analyzed. Lime stabilization had little effect on the early age mechanical and durability behavior of CEB. Design coefficients are suggested for common cement-stabilized CEB under different environmental conditions. A minimum of 4% cement content was sufficient to produce water-resistant CEB with partial incorporation of recycled aggregates.     

To be and to continue being a cog: the conservation of the Bremen Cog of 1380

The conservation project for the Bremen Cog of 1380 took 38 years from salvage to presentation of the ship to the public in the Deutsches Schiffahrtsmuseum in 2000. The ship was salvaged from the River Weser in about 2000 pieces, and stored in water tanks. A new museum was built, and the Cog reassembled from the waterlogged timbers. The ship was reconstructed with most of the weight being taken by the ceiling of the hall via a steel-rod hanging system. Then a conservation tank was built around the hull, and a novel two-step PEG-treatment applied, especially developed for the Cog. In two consecutive baths PEG 200 and PEG 3000 stabilized lesser degraded and heavily degraded wood against shrinkage, splitting, and warping. After cleaning, the wood looks dark brown, dry, and natural. The extraordinary project is regarded a success.     

铁基与铜基颜料对纸质文物的化学腐蚀降解

古籍、档案、书画、碑帖等纸质文物记录了人类社会的历史发展,是不可再生的文化遗产。然而,大量纸质文物在长期保存过程中发生了老化劣化现象,甚至造成纸质文物的永久失传。值得注意的是,部分颜料与墨水中含有的铁铜金属物种会引起纸张较为严重的腐蚀降解,使得色块或墨迹周围的纸张明显泛黄,甚至在着墨位置形成空洞。铁铜颜料引起纸质文物损害的原因复杂且多样,在其作用下纤维素高分子的反应路径与降解机理值得深入研究。本研究介绍了纸质文物中常见的铁基与铜基颜料,包括铁盐墨水、普鲁士蓝、赭石、蓝铜矿、孔雀石、醋酸铜等。总结了纸张纤维素的酸性水解、碱性降解和氧化降解反应路线,探索了金属物种作用下纸张纤维素的酸碱反应与氧化还原反应机理。其中含铁颜料的纸张纤维素主要经历芬顿(Fenton)氧化降解和酸性水解,含铜颜料腐蚀纸张纤维素的主要途径为菲林(Fehling)氧化降解和碱性降解。 本研究聚焦于铁基与铜基颜料对纸质文物腐蚀降解的化学反应机理,总结出铁铜离子参与的氧化反应是纸张纤维素加速降解的主要因素。在此基础上,提出了添加抗氧化剂以减缓氧化反应发生的纸质文物保护策略,包括预防性抗氧化剂与断链性抗氧化剂。重点介绍了络合剂配位铁铜金属离子的预防性抗氧化保护法,如使用植酸/植酸盐、溴化铵、明胶蛋白等络合剂与铁铜离子络合,以减缓氧化降解反应的发生。同时也分析了络合剂方法存在的一些问题,如植酸只能在酸性条件下使用、苯并三唑会造成颜料变色、部分抗氧化剂具有毒性等。最后,本研究针对铁基与铜基颜料腐蚀降解纸张的机理研究与保护策略提出展望。在机理研究方面,过渡金属游离态与络合态的分布情况、过渡金属引发氧化反应的条件控制、氧化降解反应与纤维素超分子结构的相互关系等仍有待研究。在保护策略方面,所选择的保护方法应当不仅可以有效减缓过渡金属对纸张的降解,而且不会对纸张纤维与颜料墨迹造成损坏。本研究从化学角度对过渡金属颜料所导致的纤维素降解演化机理提出更深刻的认识,为含有过渡金属颜料纸质文物的多方位保护提供引导和借鉴。