共查询到12条相似文献,搜索用时 46 毫秒
1.
为探讨银器物防变色缓蚀作用的机理,用AES和XPS方法研究了缓蚀剂在银表面成膜的厚度和各组分的化学状态,测测定了PMTA、MBO、MBI的普通拉曼光谱(NRS),利用表面增强拉曼散射光谱(SERS)研究几种唑系缓蚀剂防止银器物变色的表面成膜过程,复合缓蚀剂组分与银的相互作用,并讨论了其防变色作用的机理,实验结果表明,PMTA,MBI和MBO与银表面存在着较强的相互作用,由于杂环结构的差异,不同缓蚀剂在银表面上呈现不同的吸附取向,形成了更为致密的防变色保护膜,在成膜溶液中,PH值较小时有利于缓蚀剂吸附,处理时间应不少于120min.成膜溶液和含缓蚀剂的硫化钠溶液中,银电极阴极极化时(外加阴极电位≤600mV的测试范围内),复合缓蚀剂的SERS响应均随电位负移而增强,表明其可有效防止银在腐蚀介质中的变色行为。 相似文献
2.
银器文物防变色缓蚀作用机理的研究 总被引:2,自引:0,他引:2
为探讨银器文物防变色缓蚀作用的机理,用AES和XPS方法研究了缓蚀剂在银表面成膜的厚度和各组分的化学状态,测定了PMTA、MBO、MBI的普通拉曼光谱(NRS),利用表面增强拉曼散射光谱(SERS)研究几种唑系缓蚀剂防止银器文物变色的表面成膜过程,复合缓蚀剂组分与银的相互作用,并讨论了其防变色作用的机理。实验结果表明,PMTA、MBI和MBO与银表面存在着较强的相互作用,由于杂环结构的差异,不同缓蚀剂在银表面上呈现不同的吸附取向,形成了更为致密的防变色保护膜。在成膜溶液中,pH值较小时有利于缓蚀剂吸附,处理时间应不少于120min。成膜溶液和含缓蚀剂的硫化钠溶液中,银电极阴极极化时(外加阴极电位≤600mV的测试范围内),复合缓蚀剂的SERS响应均随电位负移而增强,表明其可有效防止银在腐蚀介质中的变色行为。 相似文献
3.
Thomas Davidoff 《Journal of regional science》2017,57(5):713-730
This paper reviews parts III and IV of the recent Handbook of Regional and Urban Economics. Many of the surveys within the Handbook relate to two phenomena of interest: the recent boom and bust cycle in U.S. housing markets, and the striking growth of home prices in a few global “Superstar Cities.” Real Estate and Urban economists have made progress in modeling these phenomena. There is considerable room for future research, however. There is no coherent story explaining U.S. home price movements in the 2000s that does not run afoul of important stylized facts. We also have not yet identified the relative importance of supply constraints and demand growth in the rise of Superstar City prices. 相似文献
4.
Niels Peter Lemche 《SJOT: Scandinavian Journal of the Old Testament》2016,30(1):145-155
A combined review of three volumes in the series Formation and Interpretation of Old Testament Literature. If these volumes intend to give an impression of the discussion among scholars of the Deuteronomistic History, and of the composition of the Pentateuch, the series is a failure, presenting mostly one side of the debate. On the other hand, the articles on the ancient reception history (nothing modern here) are excellent introductions into that discussion. 相似文献
5.
马峰燕 《中国历史地理论丛》2010,(2)
宋代施渚镇位于今湖州市埭溪镇。其地名变化过程包含三个阶段:唐时叫做上强,宋元时名为施渚,明清时更名埭溪。施渚镇位于连接湖州与杭州的陆路交通要道上,故北宋在此设税场征收商税。南宋时,江南运河交通地位愈发重要,施渚镇所在陆路通道之地位下降,导致该镇及税场被废除。随着商品经济的发展,明代在此兴起埭溪市,最终成长为镇。施渚镇之兴衰是其所在地区交通格局及商业格局之变迁的反映。 相似文献
6.
谢振华 《中国边疆史地研究》2020,(1):44-55,214
自曹魏以来,楼兰文书一直行用中原纪年,却于晋武帝泰始六年(270)中断。根据楼兰简纸文书、元康三年(293)苻信简等出土资料,结合传世文献,作者认为学界已有树机能叛乱使纪年中断的观点恐不能成立,苻信简透露出西部鲜卑南下滋扰,西晋为此采取了收缩政策。张轨刺凉后,彻底肃清了河西寇乱,重建了楼兰的屯戍,楼兰文书得以再现西晋正朔。 相似文献
7.
唐代前期都督府探讨 总被引:1,自引:0,他引:1
李青淼 《中国历史地理论丛》2006,21(4):66-77
有鉴于前人对唐代都督府认识的分歧,本文从文献的角度论证了今人观念下的都督府自唐代建立至安史之乱的不同职能,即军政职能、民政职能、监察职能。并重点阐述了前两种职能所依据的社会背景,二者之间的相互转化,以及三种职能下都督府与常州之关系,力图解决困扰都督府研究的一些问题。 相似文献
8.
《African Historical Review》2013,45(2):58-65
ABSTRACTMuthi, intelezi and associated rituals have played an important role in the lives of Africans for many centuries. For almost everything they do, muthi and rituals are applied, more so during times of war. Controversy around the use of intelezi, muthi, ritual killing and the role of izinyanga in, prior to and during the colonial period, is well documented. This paper, first, challenges the Comaroffian analysis of the subject which purports to contextualise the ‘deployment, real or imagined, of magical means for material ends’. They add that the discourse is entirely about ‘modernity’ and ‘neoliberalism’. Here I fundamentally disagree with this explanation; I indicate that it is a cultural continuity. The paper contends that ritual killing and muthi use continues into the present and was prevalent during the political violence in KwaZulu-Natal during the 1980s and 1990s. Secondly, the paper will discuss the centrality of the use of muthi during the violence. I reason that izinyanga played a clandestine but powerful role in this violence. In this, they were at the core of the violence and of the rise of warlords to power in the region. In this paper, I will also present reasons (or offer recommendations) why historians should pay attention to these practices in the recent past, as well as in colonial times. For one thing, they are a means of understanding the present. However, in many ways, because of its reliance on oral histories and insider content, this paper is neither history nor ethnography, but could be described as historical ethnography. 相似文献
9.
隋唐长安辖县乡里考新补 总被引:2,自引:0,他引:2
程义 《中国历史地理论丛》2006,21(4):93-105
隋代长安城下辖大兴、长安二县,唐代为万年、长安二县。它们的郊区,据宋敏求《长安志》记载共有104乡。但其乡名、里名及其位置多已淹没无闻。武伯纶曾据唐代墓志资料补出了近70个乡的名称,并推定了大多数乡的位置。本文在武伯纶等人论文的基础上,利用新出墓志资料补出了隋代14乡、5里,唐代16乡、33村、19里。唐代的乡名基本沿用隋代之旧。唐代的乡与里分属不同的系统,之间无统辖关系。清代董曾臣所谓“唐长安有50乡”,是因版本而致误,唐长安的乡数应以宋敏求的记载为准。 相似文献
10.
Wang Dongjie 《中国历史研究》2016,49(3):152-174
ABSTRACTGuanhua (official language), Guoyu (national language), and Putonghua (common language) are generally regarded as different names for the same thing in different eras, but from the perspective of cultural history, there are many subtle semantic differences between these three concepts, symbolizing how different social classes and political groups defined their particular experiences, expectations, and efforts to take action. Guoyu, which replaced Guanhua in the late Qing Dynasty, is closely bound up with the construction of modern nationalism. In the 1930s, leftist intellectuals imbued Putonghua with strong proletariat attributes and overtones of indigenous and ethnic equality, wielding it as a tool for critiques against Guoyu. Although Putonghua returned to certain key positions of Guoyu after the mid-1950s, it putatively emphasized the legacy of the leftist language movement, and represented a new political identity. Through these “proper names” for the standard language, it was possible not only to launch a political and social “revolution,” but also to smooth over the historical rifts that this engendered, by repeatedly revising the concepts of “written” and “standard” to form a linear national narrative. 相似文献
11.
周晓薇 《中国历史地理论丛》2007,22(3):113-120
古代"豐都"与"酆都"的名称与概念内涵日渐混淆,以致在文献记载中不仅出现了历史地理观念上的错谬,亦在历史的演化轨迹与人文意义上相悖甚远。本文旨在缕析文献之错综,梳理载记之复杂,以期为"豐都"与"酆都"的演变正本清源,并阐释其地理与文化理念。 相似文献
12.
《弘历鉴古图》是清代宫廷画家姚文瀚创作的一幅乾隆皇帝"御容"图像。该图磨损较重,在卷藏过程中出现的霉变,导致受损部位纸质糟朽,一些重要画意脱离画心粘在背纸之上。此图因破损情况比较特殊,修复方法也因此十分复杂,本文即针对其修复情况所作的探讨。 相似文献