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1.
黄铜器表面着色方法的研究   总被引:3,自引:0,他引:3  
在总结古代铜器表面处理的文献基础上一通过化学成膜探讨含锌32%-36%的黄铜试样表面着色的方法,通过调整和控制试液的浓度、温度、酸度及浸泡时间的实验,确定黄铜表面栗色膜形成的最佳条件。对表面形成的粟色膜用多种实验手段进行了测定,结果表明栗色股厚度约为8μm主要组成为Cu2O。并对化学过程中形色栗色膜的机理作了初步探体  相似文献   
2.
明墓出土的历书,粘连固结成块,脆硬易于折断。通过实验分析研究,探明其主要原因可能是木质素选择性地吸附的钙铁离子与蛋白质的分解物形成复杂物质,沉积在纸上,渗入书内所致。故揭取该历书的关键是去除钙离子,EDTA二钢,碱性过氧化氢、气相二氧化硅等的分步处理,使脆硬的纸张软化,再逐页分离揭取,然后再去除色素沉淀物,终于恢复了书的原貌。  相似文献   
3.
A human skull, buried about 2500 years ago in a Bronze Age cemetery at Jinggouzi, a site of an important ethnic group in ancient China, appeared to have characteristics of fibrous dysplasia. The CT images indicated a reduction in bone density and relatively homogeneous lesions. More features were revealed using CT reconstruction techniques. Lesions seen in low‐magnification images using a 3D deep‐field microscope had an irregular honeycomb‐like structure. At higher magnification, the trabeculae morphology and the gaps between the trabeculae were irregular and varied in size and shape. Paraffin‐embedded specimens stained with HE showed trabeculae with tortuous irregular arrangements varying in shape and width. The irregular trabeculae of woven bone has been described as having fibrous dysplasia. Molecular analysis of the GNAS gene indicated no mutation. This provides a non‐invasive approach for us to make more comprehensive diagnoses and to assist research into ancient human diseases.  相似文献   
4.
正It is just the dawn,but the sheepfolds have already begun to move restlessly.Sunlight makes its way in.Tashi Tsedan and Redan open the sheepfolds one after another.Flocks of sheep suddenly gush out like an influx of water from an opened gate.These two herdsmen from Jirong Village in Drik Town of Gampa County are fulfilling their duty grazing these flocks of Gampa sheep,a well-known breed of Tibetan sheep.  相似文献   
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洪武年间,湖广各府级中心城治、西南少数民族等"寇乱"为患地区率皆设立卫所、筑城守御,并辅以巡检司、土司等多重防御力量。在其障护之下,腹里州县安全无虞,实无修固城防之必要。自洪武朝以至宣德朝,湖广地区修筑、维护城池主要限于驻军各地,对于其他众多普通州县并未从严要求,各地不修城的情形相当普遍。正是洪武朝奠定的颇为严密的区域安全防御体系保障了地方安定,为明前期实行这种相对宽松的筑城政策创造了条件。一些学者所谓明代"一贯积极、严厉的"筑城政策似乎并不完全切合明前期的实际。  相似文献   
7.
The Hui-style residence is an important architectural heritage of China. The hollow wall structures are widely used to build its exterior wall system. However, the thermal performance of the hollow wall is no longer able to meet the new energy-saving and environmental requirement. This article describes a laboratory study of the development of foamed mortar (FM), with the potential for use in thermal upgrading of the Hui-style hollow wall system without dramatically changing its traditional structure. The key early age, physical, mechanical and thermal properties were systematically measured. Two extended models were respectively developed to calculate compressive strength and thermal conductivity, as a function of porosity. Environment chamber test was also employed to investigate the effectiveness of this novel thermal upgrading approach and the results show that filling the voids with FM can effectively improve the overall thermal resistance of the hollow wall system by 44%, which is almost equal to the overall thermal resistance when using the more expensive commercial inorganic stucco system. In addition, the combination of these two methods yielded an overall thermal resistance of 0.701 m2·K/W, which is even higher than 0.67 m2·K/W for the code required in the hot summer/cold winter climate zone.  相似文献   
8.
秦汉帝国是伴随"新地"的推展和边界的扩张而确立的。政府在派遣"新地吏"同时,往往推行徙民实边、行役戍边政策。在后来的发展中,实边较戍边更为边策所重。其原因既涉及财政、舆论,也有对防御效能的考虑。两汉时期,内地与边郡之间的差别有所扩大,影响到朝廷内外政策的差异。边郡军事负担甚巨,而且因军队屯驻造成经济残破与社会动荡。边郡维持运转,常需邻郡供给、中央调控、募民输粟及军士屯田。"文景之治"、"光武中兴"中轻徭薄赋的惠政,与边政状况直接相关。  相似文献   
9.
<正>On the snowy highland,the splendid view of mountains and waters vie with each other;the birds and beasts stroll idly as in a courtyard,and the flourishing woods and grasses stretch as far as the eyes can see.Is"Shambhala"a fairyland?Over the years,the central government and Tibet have focused on protecting the highland ecology and have attained impressive achievements.Under the blue sky  相似文献   
10.
The study implements the performance-based analysis and design methodology to assess the seismic vulnerability of a coal-fired power plant and to optimally design its equivalent pendulum-type tuned mass damper system such that the direct losses are minimized. A building-specific total loss ratio is developed to link the component level losses with the total repair cost of the original structure. The optimal system configuration is finally derived for cases with the minimum loss. The study demonstrates a systematic way of achieving the optimal pendulum-type tuned mass damper design with considerations of uncertainties in earthquake inputs and the combined component level damages.  相似文献   
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