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排序方式: 共有472条查询结果,搜索用时 15 毫秒
1.
19世纪末,我国西北地区开始有纸质文物的考古发现,其后纸质文物在多地考古发掘中均见出土.它们品种多、数量大,加工工艺、写印材料独特,时代自汉代至明清,其中的早期文物尤为珍贵.因其出土环境复杂,保护修复工作难以直接借助传统技术和现有科技,特别是潮湿环境和干燥潮湿交替环境下出土纸质文物的保护修复往往遭遇瓶颈.目前学界在科学分析检测、造纸工艺研究、科学信息提取等科学化研究方面取得了一定成就,但对糟朽类文物的病害机理、保护修复技术等研究还远远不够.因此,当务之急是开展本体材质、劣化与粘连机理研究,探究多因素协同作用对本体的长期影响和作用方式,研发新材料与新技术,并致力于探索这类文物的活化利用.  相似文献   
2.
价值多元化是中国传统书画装裱修复技艺重要的特征之一.当前书画装裱修复从业者对技艺价值认知程度不均,价值认知现状不能与多元价值共存的现实相匹配.基于非物质文化遗产保护与传承的视角,书画装裱修复从业者应从理念上重新树立多元价值观、方法上加强现代科技手段的有效介入、理念上重视传承人整体情况的深入探求、行动上加快技艺科学化研究进程等几个方面来全面构建技艺多元价值体系.  相似文献   
3.
Monitoring is deemed crucial for the incentivization of a decentralized organization, but its function relies on information transparency between the central authority and the delegated individuals. We test this hypothesis by considering changes in the fiscal behavior of Chinese county governments following an exogenous fiscal reform in 2004/2005 that removed information obstacles between provinces and counties. Employing data on 590 Chinese counties from 2000 to 2009, we find that counties in the reform provinces adopt a more proactive fiscal policy after the reform, suggesting that they become more incentivized in the political competition for economic growth. Such effects are stronger in counties with fewer competing peers and counties with either high or low ranks in the records of economic growth among peers. The increase in counties' productive spending leads to higher economic growth in later years.  相似文献   
4.
Pan, Z., Zhu, M., Zhu, Y. &; Jia, L., August 2017. A new antiarch placoderm from the Emsian (Early Devonian) of Wuding, Yunnan, China. Alcheringa 42, 10–21. ISSN 0311-5518.

Wufengshania magniforaminis, a new genus and species of the Euantiarcha (Placodermi: Antiarcha), is described from the late Emsian (Early Devonian) of Wuding, Yunnan, southwestern China. The referred specimens were three-dimensionally preserved in black shales, allowing a high-resolution computed tomography reconstruction of anatomical details. The new euantiarch is characterized by a large orbital fenestra, an arched exoskeletal band around the orbital fenestra and a developed obtected nuchal area of the skull roof. Maximum parsimony analysis, using a revised data-set of antiarchs with 44 taxa and 66 characters, resolves Wufengshania gen. nov. as a member of the Bothriolepididae, which is characterized by the presence of the infraorbital sensory canal diverging on the lateral plate, and the nuchal plate with orbital facets. New analysis supports a sister group relationship between Dianolepis and the Bothriolepididae. Luquanolepis, a coeval euantiarch from the neighboring site of the new form, is referred to the Asterolepidoidei and represents the basalmost and earliest member of the Asterolepidoidei.

Zhaohui Pan* [], Min Zhu* [], You’an Zhu? [] and Liantao Jia [] Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, PO Box 643, Beijing 100044, PR China. *Also affiliated with University of Chinese Academy of Sciences, Beijing, 100049, PR China. ?Also affiliated with Uppsala University, PO Box 256, 751 05 Uppsala, Sweden.  相似文献   
5.
L. Jiang  W. Pan  C. Cai  L. Jia  L. Pan  T. Wang  H. Li  S. Chen  Y. Chen 《Geofluids》2015,15(3):483-498
Permian hydrothermal activity in the Tarim Basin may have been responsible for the invasion of hot brines into Ordovician carbonate reservoirs. Studies have been undertaken to explain the origin and geochemical characteristics of the diagenetic fluid present during this hydrothermal event although there is no consensus on it. We present a genetic model resulting from the study of δ13C, δ18O, δ34S, and 87Sr/86Sr isotope values and fluid inclusions (FIs) from fracture‐ and vug‐filling calcite, saddle dolomite, fluorite, barite, quartz, and anhydrite from Ordovician outcrops in northwest (NW) Tarim Basin and subsurface cores in Central Tarim Basin. The presence of hydrothermal fluid was confirmed by minerals with fluid inclusion homogenization temperatures being >10°C higher than the paleo‐formation burial temperatures both in the NW Tarim and in the Central Tarim areas. The mixing of hot (>200°C), high‐salinity (>24 wt% NaCl), 87Sr‐rich (up to 0.7104) hydrothermal fluid with cool (60–100°C), low‐salinity (0 to 3.5 wt% NaCl), also 87Sr‐rich (up to 0.7010) meteoric water in the Ordovician unit was supported by the salinity of fluid inclusions, and δ13C, δ18O, and 87Sr/86Sr isotopic values of the diagenetic minerals. Up‐migrated hydrothermal fluids from the deeper Cambrian strata may have contributed to the hot brine with high sulfate concentrations which promoted thermochemical sulfate reduction (TSR) in the Ordovician, resulting in the formation of 12C‐rich (δ13C as low as ?13.8‰) calcite and 34S‐rich (δ34S values from 21.4‰ to 29.7‰) H2S, pyrite, and elemental sulfur. Hydrothermal fluid mixing with fresh water in Ordovician strata in Tarim Basin was facilitated by deep‐seated faults and up‐reaching faults due to the pervasive Permian magmatic activity. Collectively, fluid mixing, hydrothermal dolomitization, TSR, and faulting may have locally dissolved the host carbonates and increased the reservoir porosity and permeability, which has significant implications for hydrocarbon exploration.  相似文献   
6.
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。  相似文献   
7.
古官玺中涉及的地名颇多,其研究对古文字、古地理及古玺分域研究等方面都具有重要价值。本文从玺文的形体分析角度出发,对《古玺印菁华》收集的三方官玺予以考证,提出一些新的观点。  相似文献   
8.
光绪二十一年三月二十三日李鸿章在《马关条约》上签字画押。①条约规定,从签画到换约,限期二十一日,即截止四月十四日夜十二点钟,“两帝国政府彼此不允批准和约,无庸告知,即将此约作为废止”②。这短暂的21天为清政府的换约决策提供了思考的时间。其间,清廷一度谕令前敌主帅刘  相似文献   
9.
(2006年8月21日)同志们:中国地方志协会年鉴工作专业委员会首届学术年会今天在乌鲁木齐市召开了。这次学术年会,中国地方志指导小组办公室非常重视,年鉴工作专业委员会做了认真的组织和筹备,新疆维吾尔自治区地方志编委会和乌鲁木齐市委、市政府给予了大力支持,承办会议的乌鲁木齐市党史地方志办公室的同志们,为会议的顺利召开,做了大量的、周密的准备工作,付出了辛勤劳动。在此,我谨代表中国地方志指导小组办公室、中国地方志协会年鉴工作专业委员会,向新疆维吾尔自治区地方志编委会、乌鲁木齐市委、市政府的领导同志及乌鲁木齐市党史地方…  相似文献   
10.
安徽巢湖放王岗出土西汉漆器漆膜测试分析   总被引:6,自引:6,他引:0  
为了解放王岗出土漆器的髹漆技术,采用了漆膜切片技术、X射线衍射粉末法、傅立叶红外光谱法和显微镜等分析方法对漆器残片进行了分析。实验结果表明:大部分的漆膜包含1~3层髹漆层,一些漆膜中存在着漆灰层;采用了HgS作为漆膜的红色呈色颜料;可能采用了混合大漆和其它有机物的漆料;特别是漆膜中发现了含量约在5%左右的石英颗粒,其成因和作用值得现代漆器业去研究。  相似文献   
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