期刊文献+
共找到6篇文章
< 1 >
每页显示 20 50 100
西北屯戍汉简中的“窅”和“萆” 被引量:2
1
作者 聂丹 《敦煌研究》 CSSCI 北大核心 2015年第2期106-110,共5页
在西北屯戍汉简的守御器簿中出现了经常连用的"窅"和"萆"字,还分别与"瞀""冒"和"辟",构成"皮窅草萆、皮瞀草萆、皮冒草萆、羊皮冒萆、草辟及冒"等结构。不少学者对"... 在西北屯戍汉简的守御器簿中出现了经常连用的"窅"和"萆"字,还分别与"瞀""冒"和"辟",构成"皮窅草萆、皮瞀草萆、皮冒草萆、羊皮冒萆、草辟及冒"等结构。不少学者对"皮窅"进行过研究,未得其义,对"萆"的研究则几乎没有。又有学者认为:两者经常连用,似乎与"胄、甲"相当。通观西北屯戍汉简全部文例,发现"胄、甲"自有其稳定的词语表达。据我们研究,"窅"和"萆",是斥候(侦察兵)候望时的必备装备,每一亭隧仅有一枚。"窅",是斥候的瞭望器具,"萆",是斥候的防御隐蔽装备。 展开更多
关键词 汉简 候望
下载PDF
Climate Changes in Brazil: the Expected Financial Benefits by Implementing Smart Grids as a Mitigation and Adaptation Strategy
2
作者 Débora de Sāo José José Ntmo Fidalgo 《Journal of Environmental Science and Engineering(B)》 2017年第10期515-520,共6页
This research aims to estimate the long-term financial benefits of using smart grids to mitigate and adapt the power sector to climate change. In order to do that, twelve scenarios were analyzed applying an energy acc... This research aims to estimate the long-term financial benefits of using smart grids to mitigate and adapt the power sector to climate change. In order to do that, twelve scenarios were analyzed applying an energy accounting model (LEAP (Long-range Energy Alternatives Planning System)) that was developed using Brazilian historical data from 1970 to 2015. To conduct the analysis, the Sathaye and Ravindranath's three steps methodology was used. The main final results include a long-term cost-benefit analysis that is developed for each considered scenario. The initial phase includes the analysis of the projections for the power sector up to 2030. The following phase consists on the estimation of costs for operation, maintenance, losses and new electrical projects investments. And finally, all scenarios' results were compared and the benefits of implementing smart grids in the sector were estimated. The attained results show that smart grid implementation would contribute to reduce electricity tariffs, the generation costs as well as the costs associated with theft and fraud. 展开更多
关键词 Adaptation to climate change climate change mitigation power systems smart grid financial analysis Brazil.
下载PDF
Contraindications for video capsule endoscopy 被引量:2
3
作者 Dirk Bandorski Niehls Kurniawan +4 位作者 Peter Baltes Reinhard Hoeltgen Matthias Hecker Dominik Stunder Martin Keuchel 《World Journal of Gastroenterology》 SCIE CAS 2016年第45期9898-9908,共11页
Video capsule endoscopy(VCE) has been applied in the last 15 years in an increasing field of applications. Although many contraindications have been put into perspective, some precautions still have to be considered. ... Video capsule endoscopy(VCE) has been applied in the last 15 years in an increasing field of applications. Although many contraindications have been put into perspective, some precautions still have to be considered. Known stenosis of the gastrointestinal tract is a clear contraindication for VCE unless surgery is already scheduled or at least has been considered as an optional treatment modality. In patients with a higher incidence of stenosis, as in an established diagnosis of Crohn's disease, clinical signs of obstruction, prior radiation or surgical small bowel resection, a preceding test with the self-dissolving patency capsule can override this contraindication. Endoscopic placement of the capsule should be considered in patients with swallowing disorders to avoid aspiration. Esophageal or gastric motility disorders may require endoscopic capsule transport or application of prokinetics if the real-time viewer proofs delayed transit. In pregnant women, VCE should be restricted to urgent cases where diagnosis cannot be postponed after delivery, as data on safety are missing. There is theoretical and clinical evidence that patients with implanted cardiac devices such as a pacemaker, cardioverters or left heart assist devices, can safely undergo VCE in spite of still existing contraindication by manufacturers. Children from the age of 2 years have safely undergone VCE. Although video capsules are not proven safe with magnetic resonance imaging(MRI), first single cases of patients incidentally undergoing MRI with an incorporated capsule have been reported, showing susceptibility artifacts but no signs of clinical harm. 展开更多
关键词 Video capsule endoscopy CONTRAINDICATIONS STENOSIS PACEMAKER ASPIRATION PREGNANCY Magnetic resonance imaging
下载PDF
Paleoclimate data assimilation: Its motivation, progress and prospects 被引量:4
4
作者 FANG Miao LI Xin 《Science China Earth Sciences》 SCIE EI CAS CSCD 2016年第9期1817-1826,共10页
Reconstructing past climate is beneficial for researchers to understand the mechanism of past climate change, recognize the context of modern climate change and predict scenarios of future climate change. Paleoclimate... Reconstructing past climate is beneficial for researchers to understand the mechanism of past climate change, recognize the context of modern climate change and predict scenarios of future climate change. Paleoclimate data assimilation(PDA), which was first introduced in 2000, is a promising approach and a significant issue in the context of past climate research. PDA has the same theoretical basis as the traditional data assimilation(DA) employed in the fields of atmosphere science, ocean science and land surface science. The main aim of PDA is to optimally estimate past climate states that are both consistent with the climate signal recorded in proxy and the dynamic understanding of the climate system through combining the physical laws and dynamic mechanisms of climate systems represented by climate models with climate signals recorded in proxies(e.g., tree rings, ice cores). After investigating the research status and latest advances of PDA abroad, in this paper, the background, concept and methodology of PAD are briefly introduced. Several special aspects and the development history of PAD are systematically summarized. The theoretical basis and typical cases associated with three frequently-used PAD methods(e.g., nudging, particle filter and ensemble square root filter) are analyzed and demonstrated. Finally, some underlying problems in current studies and key prospects in future research related to PDA are proposed to provide valuable thoughts on and a scientific basis for PDA research. 展开更多
关键词 Climate reconstruction Paleoclimate modeling PROXIES Data assimilation
原文传递
Methanogenesis and Methanotrophy in Soil: A Review 被引量:11
5
作者 N.SERRANO-SILVA Y.SARRIA-GUZMN +1 位作者 L.DENDOOVEN M.LUNA-GUIDO 《Pedosphere》 SCIE CAS CSCD 2014年第3期291-307,共17页
Global warming, as a result of an increase in the mean temperature of the planet, might lead to catastrophic events for humanity. This temperature increase is mainly the result of an increase in the atmospheric greenh... Global warming, as a result of an increase in the mean temperature of the planet, might lead to catastrophic events for humanity. This temperature increase is mainly the result of an increase in the atmospheric greenhouse gases (GHG) concentration. Water vapor, carbon dioxide (CO2), methane (CH4) and nitrous oxide (N20) are the most important GHG, and human activities, such as industry, livestock and agriculture, contribute to the production of these gases. Methane, at an atmospheric concentration of 1.7 gmol tool-1 currently, is responsible for 16% of the global warming due to its relatively high global warming potential. Soils play an important role in the CH4 cycle as methanotrophy (oxidation of CH4) and methanogenesis (production of CH4) take place in them. Understanding methanogenesis and methanotrophy is essential to establish new agriculture techniques and industrial processes that contribute to a better balance of GHG. The current knowledge of methanogenesis and methanotrophy in soils, anaerobic CH4 oxidation and methanotrophy in extreme environments is also discussed. 展开更多
关键词 anaerobic CH4 oxidation biological production global warming methanogenic archaea methanotrophic bacteria
原文传递
Hydrological monitoring and seasonal forecasting:Progress and perspectives
6
作者 汤秋鸿 张学君 +5 位作者 段青云 黄诗峰 袁星 崔惠娟 李哲 刘星才 《Journal of Geographical Sciences》 SCIE CSCD 2016年第7期904-920,共17页
Hydrological monitoring and seasonal forecasting is an active research field because of its potential applications in hydrological risk assessment, preparedness and mitigation. In recent decades, developments in groun... Hydrological monitoring and seasonal forecasting is an active research field because of its potential applications in hydrological risk assessment, preparedness and mitigation. In recent decades, developments in ground and satellite measurements have made the hydrometeorological information readily available, and advances in information technology have facilitated the data analysis in a real-time manner. New progress in climate research and modeling has enabled the prediction of seasonal climate with reasonable accuracy and increased resolution. These emerging techniques and advances have enabled more timely acquisition of accurate hydrological fluxes and status, and earlier warning of extreme hydrological events such as droughts and floods. This paper gives current state-of-the-art understanding of the uncertainties in hydrological monitoring and forecasting, reviews the efforts and progress in operational hydrological monitoring system assisted by observations from various sources and experimental seasonal hydrological forecasting, and briefly introduces the current monitoring and forecasting practices in China. The grand challenges and perspectives for the near future are also discussed, including acquiring and extracting reliable information for monitoring and forecasting, predicting realistic hydrological fluxes and states in the river basin being significantly altered by human activity, and filling the gap between numerical models and the end user. We highlight the importance of understanding the needs of the operational water management and the priority to transfer research knowledge to decision-makers. 展开更多
关键词 hydrological monitoring hydrological forecasting UNCERTAINTY MODELING remote sensing climate model
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部