首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   220篇
  免费   5篇
  2023年   1篇
  2022年   3篇
  2021年   4篇
  2020年   5篇
  2019年   6篇
  2018年   2篇
  2017年   12篇
  2016年   15篇
  2015年   4篇
  2014年   6篇
  2013年   32篇
  2012年   12篇
  2011年   10篇
  2010年   14篇
  2009年   12篇
  2008年   12篇
  2007年   11篇
  2006年   9篇
  2005年   9篇
  2004年   6篇
  2003年   5篇
  2002年   6篇
  2001年   2篇
  2000年   4篇
  1999年   2篇
  1997年   1篇
  1996年   3篇
  1995年   1篇
  1994年   3篇
  1993年   9篇
  1991年   2篇
  1988年   2篇
排序方式: 共有225条查询结果,搜索用时 328 毫秒
61.
长江三峡库区旅游资源可持续利用研究   总被引:9,自引:0,他引:9  
现代旅游业的发展建立在资源的可持续利用和环境的有效保护基础上,文章从长江三峡库区旅游业的发展现状、存在的问题、旅游资源的特征以及三峡工程兴建给长江三峡库区旅游业发展带来的深远影响分析入手,探讨了长江三峡旅游资源的开发模式与可持续利用问题。提出了三峡库区旅游资源的开发应在遵循非均衡空间开发格局的同时实施"点-轴-网"战略开发模式,并指出"一线二区三精品"的战略开发重点和可持续利用的途径。  相似文献   
62.
拜城多岗墓地是新疆西部发现的墓葬数量较多的墓葬群之一,墓葬情况复杂,葬俗葬式多样,是早期铁器时代的研究资料。本文对于采集到的该墓地41具人骨进行碳氮稳定同位素分析,探讨多岗居民的饮食状况;并结合墓葬类型、随葬品种类,男女性别以及考古学分期等对不同条件人们的食物差别进行考察,为该区域早期铁器时代居民的饮食结构研究提供依据。分析结果显示,多岗居民δ15N平均值为12.56‰,表明食物中有较多的肉类;而δ13C分析平均值为-14.77‰,相应植物类食物中C4类植物为40%左右。参考周边遗址的出土遗存,其C4类植物应为粟或黍。  相似文献   
63.
Among the multiple proxies for detecting maize in precontact economies is the use of δ13C analysis of carbonized residues from ceramic cooking vessels. Although maize horticulture was widely established in Eastern North America (ENA) by A.D. 1000, there are carbonized residues from ceramic assemblages after this date that lack the elevated δ13C values indicative of the presence of maize. This may be due to the true absence of maize, or other factors including the masking of maize. Prior experimental research by Hart et al. demonstrated that the addition of C3 plants or consumers to two part mixes with maize can mask maize presence even when maize is the dominant ingredient. Here we investigate the effect of alkali processing of maize (nixtamalization) on δ13C using the widespread ENA process of boiling maize kernels with wood ash, a C3 product, to create hominy. Our experiments test whether or not the process of hardwood ash nixtamalization can mask the presence of maize in adhering carbonized residues by depleting δ13C values, and whether there is a reciprocal δ13C enrichment effect on the hardwood ash employed in nixtamalization. Overall, there is substantial δ13C depletion of residues when maize is cooked with hardwood ash, and hardwood ash cooked with maize shows the reciprocal enrichment. Therefore, the depleted values after the adoption of maize may be false negatives due to the nixtamalization process.  相似文献   
64.
Stone tools were knapped, not built. This truism means that tools were reduced from larger pieces in the production process. But many tools were further reduced in use, to repair damage or as edges dulled. Reduction reduced size (trivially), but also changed the proportions among tools' elements or dimensions. Such allometric variation (change in proportion as a function of change in size) is useful to estimate the degree of reduction that tools experienced. Reduction itself is a measure of curation, a theoretical concept of great interest in lithic studies and Paleolithic archaeology. To determine the reduction that archaeological tools experienced, we must compare their size and proportions at first use to the same properties at discard that we directly measure. By now many size estimates can be made from discarded tools. Some are experimentally tested but few are validated using direct ethnoarchaeological controls. We validate two allometric reduction measures—ratios of plan area to thickness and of an estimate of original to discarded volume—against direct measures of use and reduction in ethnographic Gamo hidescrapers from Ethiopia.  相似文献   
65.
战国秦汉时期长江中游地区气候状况研究   总被引:1,自引:0,他引:1  
本文根据历史文献、考古材料和钻孔孢粉资料等,对战国秦汉时期长江中游地区的气候状况进行了初步的探讨。结果表明:战国初期,该地气候温暖湿润;战国中后期至西汉武帝后期,气温下降,气候温凉,极端寒冷事件不断出现;约从公元前100年始,气温明显回升,至公元初年前后,长江中游地区复为温暖湿润的气候环境;公元之初的新莽政权时期,气候经历了由暖而寒的历史转变,降温过程大致持续到东汉明帝时期;之后至东汉中后期,气候暖湿,尤其是冬季气温相对较高;东汉后期,气候再度出现了幅度不大的波动,标志着魏晋南北朝时期大降温的开始。此间气候虽屡有起伏,但总体而言,战国秦汉时期长江中游地区的气候仍以暖湿为主,气温略高于今,或与现今差别不大。在干湿状况方面,具有干湿相间的特点。  相似文献   
66.
上海博物馆藏董其昌《山水》册(共十开),为天启四年(1624)元旦所作,实并非董氏真迹。据考,该年四月董其昌才抵京。同时,该册对题均节录自董氏及明清书画著录著作与晚清文学笔记中,其第二开对题,与故宫博物院藏董氏癸酉(1633)夏五所作《董范合参图》轴题跋相同。再考《山水》册笔法,嫩弱飘浮,墨色平淡,与典型的董其昌风格相差甚远,更无其生拙秀逸之气;而《董范合参图》轴,用笔亦尖劲细碎,全幅墨气滞涩,艺术水准远不及故宫博物院藏董氏十二年前所作《仿古山水图》册,亦无法企及董氏卒前一年所作的《关山雪霁图》卷。可见,《山水》册和《董范合参图》轴非董氏本家之作。  相似文献   
67.
胡进驻 《华夏考古》2020,(1):65-73,122
周人在战国以前没有毁庙制度,坚持践行宗庙都宫制。天子七庙制度可能是战国以降才逐渐确立的。两周姬姓诸侯多以所出之周王为庙尊太祖。  相似文献   
68.
This article deals with the roles of ambiguity and discretion in the governing of migration and how they contribute to the marginalisation of migrants at the borders of EUrope. Building on ethnographic research and interviews conducted in Sicily, it connects legal-institutional ambiguities of two recent policy interventions in the field of migration governance in Italy – the Security Decree-Law and the Hotspot Approach – to the discretionary practices by public officials tasked with their implementation. By theoretically and empirically tracing the co-constitutive relationship of ambiguity and discretion, the article draws on and contributes to recent inquiries into grey areas of governance, particularly in the field of (critical) border regime studies. Based on two distinct cases, it analyses how ambiguity and discretionary local practices are related both to each other and to the contemporary fragmentary reconfiguration processes of the EUropean Migration and Border Regime, and shows how they intersect to form spatio-juridical grey areas that foster the spatial and social marginalisation of migrants in EUrope.  相似文献   
69.
C. Greco  C. Otero 《Archaeometry》2016,58(5):848-862
The region of the Central and South Andes was, in about the ninth and 15th centuries ad , the stage for the development of political systems tending towards demographic centralization in villages with defensive structures, known as Pucará. The chronological accuracy for these phenomena still remains uncertain, mainly because it involves intervals of long and superimposed occupations, masked by the Inca domination. Thus, this paper analyses the history of the occupation at Pucará de Tilcara, one of the biggest populated centres of the Humahuaca Gorge (Quebrada de Humahuaca, Argentina). Twenty‐five radiocarbon dates are critically evaluated to judge its reliability. The Bayesian statistics show that all the dated spaces were used on a long‐term basis. The most ancient signs are in the middens and relate at least to the 10th century ad , and the occupation of the housing areas could be calculated to the 13th and 16th centuries. A phase of higher intensity of occupation is observed during the Inca period. This redefinition of this site occupation shows the need to statistically analyse the dates in order to differentiate the phases of occupation.  相似文献   
70.
Beginning with my recollection of hearing C. P. Snow's ‘Two Cultures’ lecture, I sketch my experience of building two academic careers in succession, first in one of the natural sciences and later in the history of such sciences. I outline both the difficulties and the rewards that I encountered in crossing the alleged gulf between the sciences and the humanities, but also emphasise the diversity of cultures that I experienced within each. I describe my own encounter with the academic culture of continental Europe, within which the concept of a monolithic singular ‘Science’ could be dismissed as an ‘anglophone heresy’, and viewed from which the Two Cultures debate could seem both provincial and redundant.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号