首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
EISCAT measurements were performed during the four ROSE rocket launches. The results are presented. It is shown that the upper altitude limit of instabilities observed by in-situ measurements agrees with calculations using EISCAT results of drift and ion sound speed and assuming the two-stream-instability mechanism. The EISCAT results together with the STARE observations were used to calculate the ion velocity and the ψ-values from the dispersion relation of two-stream-instabilities. A comparison of EISCAT, STARE and in-situ measurements is discussed.  相似文献   

2.
明代留都南京设立内外守备、参赞机务等官员负责护卫留都安全,其中内守备设立最早,时间在永乐二十二年八月,外守备随即设立于次月。首任内守备应为王景弘(又名王贵通),而非郑和。  相似文献   

3.
4.
5.
A total of 51 ancient oak wood samples originating from various European archaeological sites, dating from the Neolithic period to the 18th century, were assayed for the presence of reproducible chloroplast (cp) DNA sequences. Five polymorphic chloroplast fragments were targeted. Only five of the samples could be fully genetically characterised, revealing four different oak cpDNA haplotypes. In all cases, the haplotypes detected on ancient woods and the haplotypes characterised from fresh samples from the same localities matched. Overall, this congruence is consistent with a genetic continuity between ancient and modern European oaks, confirming the hypothesis that the mapped genetic patterns largely reflect the original structure that established during the post-glacial. This stability of the genetic structure implies that, in the future, the technique could be used to infer or confirm the transport of wood by man, providing interesting perspectives for the genetic analysis of ancient woods.  相似文献   

6.
7.
8.
科学发展观与科学改革观   总被引:1,自引:0,他引:1  
张学兵 《攀登》2007,26(1):63-66
从逻辑延伸、决策意图、落实机制以及社会反应等方面可以看出,科学发展观呼唤科学改革观;科学发展观从历史观、价值观以及方法论等方面规范着科学改革观;以科学发展观为依据,科学改革观要经得住历史与现实、公平与效率、国计与民生以及“普适”与“特色”几个维度的检验。  相似文献   

9.
This paper explores the potential of stable isotope analysis to identify the approximate region of catch of cod by analysing bones from medieval settlements in northern and western Europe. It measures the δ13C and δ15N values of cod bone collagen from medieval control samples collected from sites around Arctic Norway, the North Sea, the Kattegat and the Baltic Sea. These data were considered likely to differ by region due to, for example, variation in the length of the food chain, water temperature and salinity. We find that geographical structuring is indeed evident, making it possible to identify bones from cod caught in distant waters. These results provide a new methodology for studying the growth of long-range trade in dried cod and the related expansion of fishing effort—important aspects of the development of commercialisation in medieval Europe. As a first test of the method, we analyse three collections of cod bones tentatively interpreted as imported dried fish based on a priori zooarchaeological criteria. The results tentatively suggest that cod were being transported or traded over very long distances since the end of the first millennium AD.  相似文献   

10.
11.
We report the recovery of short fragments of PCR amplifiable ancient DNA from exoskeletal fragments of the grain weevil Sitophilus granarius (L.) extracted from Roman and medieval deposits in Northern England. If DNA preservation in archaeological insect remains is widespread then many applications in the spheres of evolutionary studies and archaeology can be conceived, some of which are outlined.  相似文献   

12.
In the author's view the contemporary detente and the spirit of Helsinki may spread historical optimism like that established after the end of World War I. The likeness of mentality leads to a retreat in fashion everywhere, and archaeology will hardly be an exception. Like some others the author also predicts an archaeological structuralism and considers its possible realization with respect to the ‘damned question’ of archaeology ‐ the change of cultures. There has here been sounded an unexpected call to dig less, and one more expected ‐ to theorize more.  相似文献   

13.
本通过检视甲骨字中独休象形而具备部属字关系的部首,归纳出126个理论上是甲中最早发生的部首字。  相似文献   

14.
鸠摩罗什是魏晋姚秦时代的名僧,历经坎坷来到长安后,积极致力于佛经翻译和教化事业,他对于中国佛学及佛教献学都着特别的贡献。对于佛学而言,通过鸠摩罗什的译介,使龙树中观派般若学说在中国得到弘传;开启了成实宗及隋唐各宗派的兴起,使成实宗成为中土较早的佛教宗派之一;使大乘佛教在中国广为流传,推动了后来中国佛学的发展。对于佛教献学而言,鸠摩罗什对佛教献的中国化作出了突出的贡献;他有计划、系统地翻译大乘典籍,奠定了汉大藏经的体系结构;他不断总结前人及自己的译经经验,为后世的翻译事业提供了有益的借鉴。鸠摩罗什因此奠定了他在中国佛教历史上的重要的地位。  相似文献   

15.
This article responds to a plea for economic geographers to play greater attention to the world's resource peripheries. The article presents a detailed case study of oil and gas development offshore of Sakhalin in the Russian Far East. The study serves to illustrate the complexity of resource peripheries and to demonstrate how a critical approach to resource geographies aids economic geographic theorization of globalization. The case study focuses on how the 'greening' of global project financing has created a means by which environmental non-governmental organizations hold the international oil companies to account. The article describes the transnational advocacy network that has developed to protest against the Sakhalin-II project. The key issues are identified and the response of the operator, Sakhalin Energy, is considered. Finally, the recent actions of the Russian Government in relation to the environmental impacts of the Sakhalin-II project are examined. The article concludes by assessing the ways in which the Sakhalin case demonstrates the complex processes that construct resource peripheries and how such analyses contribute to the development of a truly global economic geography. Le 'verdissement' du financement de projets à  相似文献   

16.
17.
This article reviews the state of the two security and defence institutions available to west Europeans: NATO and the EU's common European Security and Defence Policy (ESDP). In each case, the authors assess the political maturity and stability of the institution, and then ask what it can contribute in terms of coordinated military capability to west European's strategic readiness. NATO's Prague summit in November 2002 will address the thorny issue of the next tranche of post–Cold War enlargement. But beyond the predictable debate about which candidates to admit, and what should be offered to those unsuccessful in their bid, there will be a far more urgent and important agenda to be discussed at Prague—the military capabilities of the European allies. Given that ESDP is still far from achieving its capability goals, the authors argue that the time is right for European allies to begin thinking in terms of generating a composite, joint strike force which could be configured to be interoperable with US forces and which could salvage something useful from the disheartening lack of progress in developing a European military capability.  相似文献   

18.
Intheeighthcentury,theTibetanImedicinepractitionerscreatedthelFour-VolumeMedicalCOde,whichtellsalsooftherelationshipbetweenhumanbodyandthenatureandrecordsthemedicaleffectof209medicinalherbs.Inthe19thcentury,TibetanLamasRenzinGyamcoandDainzinPuncoggatheredmedicinalplantsand,onthisbasis,createdtheirMedicinalHerbswhichrecords774medicinalherbs.DuringChina'sTangDynasty,theHanandtheTibetanenhancedexchanges.TangPrincessesWenchengandJinchengweremarriedintotheTuboKingdom,andtheTubotroopsinfil…  相似文献   

19.
20.
AcontingentofPLAmenweremarchingintheHenduanMountainsinMay1951,asazaleasblossomedinthesolitude.Intheforefront,amancarriedonhisbackabagcontainingmetersusedtomeasuredistanceandatmosphericpressureaswellasacompass.LiPu,thenaged39,wasgeologistandleaderofthecontingentofnaturalandsocialscientistssentfromChina'shinterlandtosurveytheQinghai-TibetPlateau.HehadreturnedfromBritainwithadoctoratedegree.Theappearanceofthiscontingentwassignificantinbeingthelargestscientific,andalsothefirstmultisubjectsu…  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