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61.
    
The chemical evolution of fluids in Alpine fissure veins (open cavities with large free‐standing crystals) has been studied by combination of fluid inclusion petrography, microthermometry, LA‐ICPMS microanalysis, and thermodynamic modeling. The quartz vein systems cover a metamorphic cross section through the Central Alps (Switzerland), ranging from subgreenschist‐ to amphibolite‐facies conditions. Fluid compositions change from aqueous inclusions in subgreenschist‐ and greenschist‐facies rocks to aqueous–carbonic inclusions in amphibolite‐facies rocks. The fluid composition is constant for each vein, across several fluid inclusion generations that record the growth history of the quartz crystals. Chemical solute geothermometry, fluid inclusion isochores, and constraints from fluid–mineral equilibria modeling were used to reconstruct the pressure–temperature conditions of the Alpine fissure veins and to compare them with the metamorphic path of their host rocks. The data demonstrate that fluids in the Aar massif were trapped close to the metamorphic peak whereas the fluids in the Penninic nappes record early cooling, consistent with retrograde alteration. The good agreement between the fluid–mineral equilibria modeling and observed fluid compositions and host‐rock mineralogy suggests that the fluid inclusions were entrapped under rock‐buffered conditions. The molar Cl/Br ratios of the fluid inclusions are below the seawater value and would require unrealistically high degrees of evaporation and subsequent dilution if they were derived from seawater. The halogen data may thus be better explained by interaction between metamorphic fluids and organic matter or graphite in metasedimentary rocks. The volatile content (CO2, sulfur) in the fluid inclusions increases systematically as function of the metamorphic grade, suggesting that the fluids have been produced by prograde devolatilization reactions. Only the fluids in the highest grade rocks were partly modified by retrograde fluid–rock interactions, and all major element compositions reflect equilibration with the local host rocks during the earliest stages of postmetamorphic uplift.  相似文献   
62.
This article examines the programme of land surveying and registration that was undertaken by the British-led administration of the Anglo-Egyptian Sudan in the period 1898–1914. The Legal Secretary, Edgar Bonham Carter, stated that programme was the most important project of his division in this period. Scholars have shown that the programme, known as land ‘settlement’, was used to build alliances with elites and to clarify title for European investors in the new irrigation scheme at Gezira. This article argues that, as such, the ambitions of land settlement were relatively limited. In many other colonies, and in Britain itself, politicians and administrators across the political spectrum saw the reform of private property in land as the key for addressing structural problems in agricultural labour. One might have thought that, the Sudan, land settlement might have provided a means of addressing the dependence on slave labour in agriculture. The article demonstrates that, except for a small number of administrators (including Bonham Carter), this was not the case. The general indifference to slavery itself carried through to an indifference to the transformative potential of land law. The article examines the proposals of this minority of administrators, and contrasts their views with the majority’s focus on land settlement as demonstration and opportunity to enhance state power.  相似文献   
63.
    
Most studies portray cluster knowledge bases as a given resource, tied to specific industries and locations. However, this paper challenges that view and uncovers their dynamic nature by identifying endogenous and exogenous triggering events that influence and change the cluster knowledge base mix over time. This is done by building on the theoretical concepts of pre-existing conditions, triggering events and knowledge bases and by drawing on a case study of the design cluster located in the Triangle Area of Denmark. The paper concludes that the design cluster has changed its mix of knowledge bases several times during its evolution. Starting out as a firm-driven cluster with a dominant synthetic knowledge base, it then evolved into an artistic and creative cluster with a prevailing symbolic knowledge base. In the last few years, the cluster has increasingly adopted an analytical knowledge base at the expense of other knowledge bases. These developments have caused numerous changes in both knowledge building and the sources of knowledge in and around the cluster. These findings have implications for the framing of cluster knowledge bases, considering how they emerge, change and combine, as well as how that affects clusters’ composition of actors, activities and resources.  相似文献   
64.
ABSTRACT

This paper explores how global innovation networks (GIN) within multinational companies (MNCs) act as extra-regional sources for path development in a regional innovation system (RIS) specializing in the oil and gas sector. We combine the literature on intra-firm knowledge dynamics in MNCs’ GIN with the literature on RISs to better understand their interrelatedness and their dynamics. Based on interviews with 15 MNCs located in the south-west of Norway, we find that firms are highly dependent on competence throughout the MNCs’ entire networks, as well as interaction with the overall RIS. The findings expose that MNCs’ GINs can act as extra-regional sources for path ‘extension’ in thick and specialized RISs through intra-firm mobility, observation and sharing of routines and best practice, mainly resulting in incremental innovations. We find some signs of potential path ‘renewal’, including radical innovation ideas. However, there are hampering factors linked to strong internal competition for innovation projects, pressure for local profitability and ownership motivation. At the level of RISs, new initiatives going beyond existing cluster initiatives and specializations need support.  相似文献   
65.
李清临  王然 《江汉考古》2007,(2):77-82,41
本文简要回顾了微量元素示踪法在青铜器铜料来源研究中的应用历史,分析了其应用现状,以及在一个时期内应用不理想的深刻原因。在此基础上,阐述了微量元素示踪法有效应用的前提条件,并进一步介绍了这一方法的最新进展情况。  相似文献   
66.
Saharan dust: sources and trajectories   总被引:1,自引:0,他引:1  
The Sahara is the world's largest source of aeolian desert dust, but precise information on specific sources of this material is poor and sometimes contradictory. This paper uses daily data from the Total Ozone Mapping Spectrometer (TOMS) for 1999 to identify source areas for major dust events and their trajectories of long-range transport. Two major source areas are identified: the Bodélé depression and an area covering eastern Mauritania, western Mali and southern Algeria. Both of these major dust sources are primarily driven by natural factors since they are little affected by anthropogenic activities.  相似文献   
67.
《吴越备史》的成书、流传及版本源流考   总被引:1,自引:0,他引:1  
笔者在尽可能走访了中国大陆现存《吴越备史》的所有版本、搜集抄录了37则序跋、23则著录的基础上,按照“版本实际第一,前人的著录文字对版本的描述、交代第二”以及“宁阙疑,勿妄断”两个原则,通过对各版本文字上的比对,并结合前人的序跋、著录,梳理了《吴越备史》一书的成书过程、流传过程、版本的存佚及其源流。文章的结论有三个:一,《吴越备史》的成书分三个阶段;二,《吴越备史》的流传过程;三,中国大陆现存的23个版本共有三个源流。以上三个问题的结论可从文章附录的《吴越备史版本录》、《吴越备史流传过程和版本源流示意图》及其《吴越备史流传过程和版本源流示意图说明》一目了然。  相似文献   
68.
This paper presents levels and trends of adult male mortality in India and its major states during the post-independence period applying the widowhood method on census data. It also estimates adult male mortality for all the districts from major states of India. We adjusted widowhood estimates for possible bias due to remarriages and examined the sensitivity of adjusted estimates to different scenarios of remarriage rates. Comparison of widowhood estimates with direct estimates from official sources supports the credibility of widowhood estimates. Information obtained from widows aged 40–44 and 45–49 provided the most convincing patterns of adult mortality. Trends in adult mortality suggest that maximum gain in 45q15 for India and its states occurred during 1949–1960. Adult male mortality varied substantially across the states of India. Although adult life expectancy has been rising in India, the rate of mortality reduction has been decreasing over the last few decades.  相似文献   
69.
70.
论日语请求行为得体性的实现   总被引:1,自引:0,他引:1  
请求行为普遍而且敏感,它是人类交际中不可避免的社会活动。得体性作为请求行为所必须遵循的礼貌原则,既牵涉到语言自身,又牵涉到许多诸如风俗习惯、价值观念、社会地位、人际关系、环境、地点、时间等社会文化因素。本文通过分析中国学生运用日语表达“请求”这一言语行为时出现的语用失误,探讨中日两种文化在语言语用和社交语用方面存在的差异,旨在找出隐伏在这些失误背后的、易引起误会和冲突的文化因素,并在此基础上,提出对策,以帮助日语学习者自觉改变和调整固有的框框,提高语用能力。  相似文献   
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