DUCTILITY REDUCTION FACTOR OF MDOF SHEAR-BUILDING STRUCTURES

In this paper, the results of recent studies on inelastic seismic response of MDOF shear-building structures are presented. In the last few decades, the concept of response modification factor R has been introduced and developed to account for inelastic nonlinear behaviour of structures under earthquakes. In this paper, an attempt has been made to adjust and extend this concept through introducing a modifying factor R _T . This factor is used for dynamic analysis of MDOF structures, including the calculation of inelastic response spectra. Sensitivity analysis was carried out to identify the parameters that have influence on R _T . It has been demonstrated that R _T is predominantly a function of number of stories, and accordingly a relationship has been suggested. Finally, an approximate approach has been developed for evaluating the seismic strength and ductility demands of MDOF structures.     

THE USE OF SIMPLE PULSES TO ESTIMATE INELASTIC RESPONSE SPECTRA

Inelastic response spectra are estimated for elasto-plastic SDOF systems subjected to strong earthquake ground motions by applying the strength reduction factors determined for a simple pulse to the elastic response spectrum of the ground motion. This approach relies upon similarities in the strength reduction factors computed for earthquake ground motions and for short duration pulses. The accuracy of the estimated inelastic spectra obtained using 24 simple pulse waveforms is assessed in order to identify subsets of just several pulse waveforms that are suited for this purpose. Based upon the ground motions and pulses investigated, this approach appears to be equally applicable to short and long duration ground motions and those having near-fault forward directivity features.     

贯入法原位测试夯土遗址表面强度的适用性和方法研究

表面强度是夯土遗址重要的测试指标和加固效果的评价依据。常规的强度测试方法受到取样和运输等因素的制约，不适用于作为夯土遗址如夯土补筑、表面加固等措施的效果评估方法。贯入法是成熟的砂浆强度检测方法，通过改装砂浆贯入仪降低了仪器量程；制作夯土样、室内试验验证了测试的较高精度；标定了夯土样贯入深度测量值与抗压强度的幂函数关系，确定了测强曲线。在夯土遗址现场开展原位测试，分析了布点密度对测试结果精度的影响，并利用测强曲线推算了测试区域的表面抗压强度。本研究提出了一套集“仪器改装-室内标定-现场高密度布点测试”为一体的夯土遗址表面强度评估方法，为土遗址加固效果的评价体系建设提供了参考价值。     

宋代兵力部署考察

北宋前期的军队部署实行内外相制原则,京师兵力和其他地方兵力相等,以互相牵制。这一原则在宋神宗时发生变化,大部兵力分布在西北地区,而京师地区兵力不断减少,北宋末只剩数万。南宋前期,恢复实行了内外相制的兵力部署原则,临安地区驻兵最强,后期再次颠倒,重兵多在边防。无论北宋还是南宋,兵力部署在地域上都是重北轻南,南宋政府对南部内地的防卫尤弱于北宋。北宋的东线防御立足于兵,并不依赖黄河天险,重兵都在黄河以北;南宋重兵分布在长江沿线,对天险的依赖加强,但几乎放弃了边界的另一天险——淮河,表明其防御是消极的以守为主的战略。     

Combined In-Situ and Laboratory Minor Destructive Testing of Historical Mortars

ABSTRACT

Mortar is of all masonry components the most difficult to be experimentally characterized in heritage buildings. This article investigates the possibility of combining different in-situ and laboratory minor destructive testing (MDT) techniques to assess the strength of mortar in historical brickwork. Lime mortar and clay brick walls were built in the laboratory and then tested in order to derive empirical correlation rules among three different MDT techniques: double punch test (DPT), helix pull-out test (HPT), and pin penetration test (PPT). The outcomes of this activity were used eventually to assess the mortar properties of an important historical heritage structure, Casa Puig i Cadafalch, located near Barcelona. The research is intended to promote the use of MDT in studies and conservation works on built cultural heritage by providing criteria for the evaluation of the strength of existing mortar with respectful sampling and testing techniques.     

Empires ancient and modern: strength,modernity and power in imperial ideology from the Liberal period to Fascism

This article examines the image of Empire developed in public discourse in Italy during the late Liberal period and Fascism by placing it in the context of representations of the British Empire, with which Italian imperial ambitions were compared. There is a continuity in seeing the British Empire as the expression of industrial and commercial modernity and its resultant strength, but what in the Liberal period was seen as an unparalleled superiority became under Fascism a supremacy acquired in a particular period but now exhibiting signs of decline, which Fascism should contest and surpass. Admiration of the British was mixed with disparagement: key figures expressed a competitive resentment towards Britain and its dominant international position, seeing it as the epitome of ‘modern’ imperial power against which Fascism was destined to be measured. In the 1930s signs of the British Empire's decline were sought, developing the idea in Gibbon's Decline and Fall of the Roman Empire that British domination would also rise and fall, and announcing the replacement of the ‘British order’, founded on commercial modernity and the strength of money and capital, by Fascism's new civilisation, with its authentic heritage of imperial romanità. This competitiveness towards Britain, which historiography has principally seen as a component of foreign policy (as was clear over Ethiopia), has additional significance when seen as an element of political culture that relates to the concept of the State. The autonomy and strength of the State were an important feature of Fascism's self-representation and of its legal culture, and in this light the possession of an empire came to be seen as an essential aspect of statehood and power.     

书画装裱粘接剂糊化及剥离强度研究

浆糊是书画装裱过程中主要的黏合材料,是装裱优劣和成败的关键,浆糊的制作条件决定其使用品质。为此,本工作以书画装裱用的粘接剂小麦淀粉为原料,采用快速粘度分析仪(RVA)制作糊化淀粉,研究了不同浓度、搅拌速率、搅拌时间和最高温度等制作条件对糊化曲线的影响。结果表明随着浓度的增加,衰减值和回生值分别增大,说明浆糊的稳定性差、冷却后凝胶性强。随着搅拌时间和速率的增加,最终粘度下降。最高温度对糊化特性曲线形状有影响,最高温度越高,糊化温度升高,最终粘度增大。利用物性仪测试了不同陈化时间对成糊淀粉粘接力的影响。陈化时间越长,糊化淀粉发生大分子链降解或重结晶等不同程度的老化,表现为剥离强度减小,粘附性下降。由实验结果确定浆糊的最优制作条件是浓度3g/25mL,温度95℃,搅拌时间2min,搅拌速度120r/min。以上工作在验证传统经验的同时也给书画装裱提供了理论依据。     

生物揭展剂在古书画文物揭展中的应用

揭展是书画重新装裱过程中最重要的一环。在装裱过程中所用的浆糊往往与画心、命纸很难分离,导致揭展过程复杂,且容易造成古书画的损毁。传统的水闷润揭展法对于难揭展的纸质画心极易揭晃。为解决这一问题,利用芽胞杆菌发酵产生的含有淀粉酶的胞外液制备生物揭展剂,并通过作用于宣纸老化材料验证了揭展效果。试验结果表明:枯草芽胞杆菌的发酵液去除菌体并透析后获得的生物揭展剂揭展效果较好。利用扫描电镜和拉力强度检测分析了生物揭展剂对书画文物的影响。结果表明:该生物揭展剂能够降低剥离力和纤维指数,与用水闷润相比,增加了宣纸样品在闷润后的抗拉强度,且对宣纸微观结构无明显影响;观察生物揭展后100天的样品并没有霉菌生成,表明该生物揭展剂具有很好的揭展安全性。在此基础上,对成套明代水陆画进行揭展,取得了良好效果。     

Sticking to the Stand of Chinese Culture and Promoting Cultural Self-Confidence and SelfImprovement

Sticking to the stand of Chinese culture is the basic premise of promoting cultural self-confidence and self-improvement. Only by thinking rationally about the inheritance, borrow-in, development, and promotion of culture can we grasp the essence of sticking to the stand of Chinese culture. To inherit the traditional culture, we should combine the new practice with the requirements of the times and take its essence while discarding its dross. The key to learning from foreign cultures is to give priority to ourselves and use them for our purposes. We can not swallow it all down and blindly use it. To develop socialist culture, we should, on the one hand, respect the national cultural tradition and on the other hand, constantly innovate and create a new culture. To carry forward Chinese culture, we need to meet the people’s growing spiritual and cultural demands internally and strengthen the influence of the spread of Chinese civilization, promoting Chinese culture to the world.     

红茶菌发酵液清洗丝织文物表面结晶盐的应用研究

在我国考古出土的丝织品数量多,种类丰富,但由于墓葬环境的特殊性,如棺液的浸泡等原因,丝织文物的表面形成很多结块,影响了文物的品质。因此,对此类丝织文物的清洗成为文物保护工作的重要一环。为此,本研究以唐代出土丝织文物残片表面的结块为研究对象,利用拉曼光谱和X射线衍射仪检测技术对其表面结块的成分进行分析。结果表明,结晶盐的主要成分为CaSO4.2H2O。本研究针对其结晶盐的成分,再利用显微观察、抗拉强度检测等手段分析了红茶菌发酵液对老化的现代蚕丝影响。在得出没有损伤的基础上,利用红茶菌发酵液中的生物有机酸和生物酶作为生物清洗剂清洗唐代丝织文物残片表面的结晶盐,取得了良好的清洗效果,对丝织文物本身无损伤。