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Progress of International Meridian Circle Program
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作者 WANG Chi BLANC Michel +13 位作者 ZHANG Shunrong DENARDINI Clezio Marcos LIU William SHEN Xuhui WU Jian XU Jiyao LI Hui ZHANG Qinghe REN Liwen ZHU Yajun LI Guozhu DING Zonghua LIU Zhengkuan YANG Fang 《空间科学学报》 CAS CSCD 北大核心 2024年第4期741-745,共5页
In 2024,the Chinese Meridian Project(CMP)completed its construction,deploying 282 instruments across 31 stations.This achievement not only provides a robust foundation but also serves as a reference template for the I... In 2024,the Chinese Meridian Project(CMP)completed its construction,deploying 282 instruments across 31 stations.This achievement not only provides a robust foundation but also serves as a reference template for the International Meridian Circle Program(IMCP).The IMCP aims to integrate and establish a comprehensive network of ground-based monitoring stations designed to track the propagation of space weather events from the Sun to Earth.Additionally,it monitors various disturbances generated within the Earth system that impact geospace.Over the past two years,significant progress has been made on the IMCP.In particular,the second phase of construction for the China-Brazil Joint Laboratory for Space Weather has been completed,and the North Pole and Southeast Asia networks are under active construction.The 2024 IMCP joint observation campaign was successfully conducted.To facilitate these developments,the scientific program committee of IMCP was established,following the success of 2023 IMCP workshop and the space weather school,which was co-hosted with the Asia-Pacific Space Cooperation Organization(APSCO)and sponsored by Chinese Academy of Sciences(CAS)and Scientific Committee on Solar-Terrestrial Physics(SCOSTEP).Preparations are now underway for the 2024 workshop in collaboration with the National Institute for Space Research(INPE)in Brazil. 展开更多
关键词 Chinese Meridian Project(CMP) International Meridian Circle Program(IMCP) China-Brazil Joint Laboratory for Space Weather North Pole and Southeast Asia networks
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Past,present and future of the Resonant-Mass gravitational wave detectors 被引量:2
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作者 Odylio Denys Aguiar 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2011年第1期1-42,共42页
Resonant-mass gravitational wave detectors are reviewed from the concept of gravitational waves and its mathematical derivation, using Einstein's general relativity, to the present status of bars and spherical detect... Resonant-mass gravitational wave detectors are reviewed from the concept of gravitational waves and its mathematical derivation, using Einstein's general relativity, to the present status of bars and spherical detectors, and their prospects for the future, which include dual detectors and spheres with non-resonant transducers. The review not only covers technical aspects of detectors and sciences that will be done, but also analyzes the subject in a historical perspective, covering the various detection efforts over four decades, starting from Weber's pioneering work. 展开更多
关键词 gravitation -- gravitational waves -- instrumentation: detectors
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Adhesion Studies of Diamond-Like Carbon Films Deposited on Ti6Al4V Alloy after Carbonitriding 被引量:2
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作者 Deiler Antonio Lima-Oliveira Romina Paula Castro Costa +4 位作者 Gislene Valdete Martins Evaldo JoséCorat Vladimir Jesus Trava-Airoldi Anderson Oliveira Lobo Fernanda Roberta Marciano 《Open Journal of Metal》 2012年第1期1-7,共7页
Diamond-like Carbon (DLC) coatings have attracted significant attention due to their low friction coefficient, high degree of hardness, chemical inertness, and high wear resistance as well as and their many possible u... Diamond-like Carbon (DLC) coatings have attracted significant attention due to their low friction coefficient, high degree of hardness, chemical inertness, and high wear resistance as well as and their many possible uses in metallurgical, aeronautical, and biomedical applications. However, DLC has low adhesion strength to metallic substrates. Carbonitriding was performed before DLC deposition to improve this adherence. Different concentration of nitrogen in the gas mixture was used during the carbonitriding of Ti6Al4V alloy. DLC films were subsequently grown from methane using plasma enhanced chemical vapor deposition. The samples were characterized with Raman scattering spectroscopy, nanoindentation, and tribological tests. Films from 80.0% N2 had the best friction coefficient (0.07) and a critical load of ~22 N. In the scratching test, these films had adhesive failure and they completely detached from the substrate only in the end of the tests. SEM images show carbonitring promoted a significant increase in the surface defects (homogeneously distributed) but without the presence of microcracks. EDX analysis indicated that nitrogen element was diffused throughout the thickness of the samples. Hydrogen and carbon atoms from carbonitriding formed a diffusion-barrier layer that can be used as the first step for DLC deposition. This carbonitriding can also provide a carbide layer, which serves as the precursor for the nucleation and growth of DLC films. 展开更多
关键词 Diamond-Like Carbon CARBONITRIDING Ti6Al4V Alloy
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Validation of Novel Model for Identification of Thermal Conditions in the Low Corona 被引量:1
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作者 Daniel B. Berdichevsky Jenny M. Rodríguez Gómez +1 位作者 Luis E. Vieira Alisson Dal Lago 《Advances in Aerospace Science and Technology》 2022年第1期52-84,共33页
The electron density and temperature key properties of the neutral-magnetized plasma in the solar corona, which are predicted with a novel model, provide an interesting window along the whole solar cycle. In this work... The electron density and temperature key properties of the neutral-magnetized plasma in the solar corona, which are predicted with a novel model, provide an interesting window along the whole solar cycle. In this work, we test the quantitative validity of the model and prove that the Coronal Density and Temperature (CODET) is reliable. Furthermore, this work contrasts the CODET model results with alternative observational remote and in-situ datasets during the simplest conditions of the quiescent corona near the solar minimum. This successful outcome/validation of the CODET model allowed a good qualitative density and temperature retrieval in the solar corona covering a large portion of time interval from solar cycles 23 and 24. 展开更多
关键词 Solar Corona Electron Density TEMPERATURE
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Surrogate Climate Change Scenario and Projections with a Regional Climate Model: Impact on the Aridity in South America
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作者 Sergio H. Franchito Julio P. Reyes Fernandez David Pareja 《American Journal of Climate Change》 2014年第5期474-489,共16页
The impact of global warming on the aridity in South America (SA) is investigated. For this purpose, the methodology for generating surrogate climate-change scenarios with a RCM is employed. For the present climate (C... The impact of global warming on the aridity in South America (SA) is investigated. For this purpose, the methodology for generating surrogate climate-change scenarios with a RCM is employed. For the present climate (CTRL) the RCM is initialized with and driven by ECMWF/ERA-Interim reanalysis data. Two aridity indices are used: the Budyko and the UNEP indices. The results for the CTR are in agreement with other model studies which indicate future warming;rainfall increases in southeastern South America, Ecuador and Peru and decreases in the central and eastern Amazon. In general the model reproduces the aridity in the continent compared with the observed data for both indices. The distribution of aridity over SA in surrogate climate-change scenario shows an increase of the dryness in the continent. Over Amazonia the aridity increases 23.9% (for the UNEP index) and 3.1% (for the Budyko index), suggesting that portions of the Amazonia forest are replaced by dry land area. The semi-arid zone over northeast Brazil expands westward, attaining the interior of north Brazil. In this region the aridity increases 20% (for the UNEP index) and 0.6% (for the Budyko index) indicating that areas of humid regime may be occupied by areas with dry land regime. The RCM was also integrated driven by the AOGCM ECHAM5/MPI-OM for the reference climate (CTRL2) and under A1B SRES scenario. The results for the present-day climate are similar in CTRL2 and CTRL, and are in agreement with CRU data. The distribution of the aridity for the present climate seems to be better represented in CTRL using both Budyko and UNEP indices. The changes in aridity (future climate minus control) are higher in the run forced by the A1B SRES scenario. Although the UNEP and Budyko indices show potentialities and limitations to represent the aridity distribution over SA, the changes in aridity due to a pseudo-scenario of global warming are higher using the UNEP index. 展开更多
关键词 ARIDITY in SOUTH AMERICA Surrogate Climate-Change SCENARIO REGIONAL CLIMATE Model
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Studies of Climate Change with Statistical-Dynamical Models: A Review
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作者 Sergio H. Franchito Vadlamudi B. Rao 《American Journal of Climate Change》 2015年第1期57-68,共12页
The cause-effect relationship is not always possible to trace in GCMs because of the simultaneous inclusion of several highly complex physical processes. Furthermore, the inter-GCM differences are large and there is n... The cause-effect relationship is not always possible to trace in GCMs because of the simultaneous inclusion of several highly complex physical processes. Furthermore, the inter-GCM differences are large and there is no simple way to reconcile them. So, simple climate models, like statistical-dynamical models (SDMs), appear to be useful in this context. This kind of models is essentially mechanistic, being directed towards understanding the dependence of a particular mechanism on the other parameters of the problem. In this paper, the utility of SDMs for studies of climate change is discussed in some detail. We show that these models are an indispensable part of hierarchy of climate models. 展开更多
关键词 Simple CLIMATE MODELS Statistical-Dynamical MODELS CLIMATE CHANGE
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Study of the Effects of Atmospheric Pressure in the Time Series of Muon Detector Using the Method of Spectral Analysis
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作者 Nivaor Rodolfo Rigozo 《International Journal of Geosciences》 2014年第3期239-246,共8页
This paper presented a study of the effects of atmospheric pressure in the time series of muon detector using the method of spectral analysis of iterative regression. In which it observed that the periods of 4.8, 5.7,... This paper presented a study of the effects of atmospheric pressure in the time series of muon detector using the method of spectral analysis of iterative regression. In which it observed that the periods of 4.8, 5.7, 7.0, 8.7, 10.7, 14.1, 16.2, 21.0, 31.2 and 356.7 days present in the amplitude spectrum of atmospheric pressure are also present in the amplitude spectra of muons data. Also it observed that the standardization of muons data to eliminate the effects of atmospheric pressure is efficient for periods under 7 days. 展开更多
关键词 Cosmic Rays Time Series Spectral Analysis
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Dengue Climate Variability in Rio de Janeiro City with Cross-Wavelet Transform
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作者 Suellen Araujo Franco dos Santos Hugo Abi Karam +9 位作者 Augusto José Pereira Filho lio Cesar Barreto da Silva Jose Luis Flores Rojas Julio Migue Angeles Suazo Isela Leonor Vá squez Panduro Cesar Arturo Sanchez Peñ a 《Journal of Environmental Protection》 2022年第3期261-276,共16页
Dengue is one of the most prominent tropical epidemic diseases present in the Rio de Janeiro city and Southeast part of Brazil, due to the widespread conditions of occurrence of the dengue vector, the mosquito Aedesae... Dengue is one of the most prominent tropical epidemic diseases present in the Rio de Janeiro city and Southeast part of Brazil, due to the widespread conditions of occurrence of the dengue vector, the mosquito Aedesaegypti, such as high-temperature days interlaced with afternoon or nocturnal rainstorms in summer. This work has the objective of investigating the relationships between variabilities of the El Ni?o-South Oscillation (ENSO) and greater epidemics of dengue in Rio de Janeiro city. To accomplish this goal, the analysis and signal decomposition by cross-wavelet transform (WT) was applied to obtain the cross variability associated with variations of power and phase of both signals by characteristic periods and along with the time series. Data considered in the analysis are (the decimal logarithm of normalized value) of the monthly available notifications of dengue worsening, provided by the public health system of Brazil, and the Southern Oscillation Index (SOI) Ni?o 3.4 data, provided by the National Oceanic and Atmospheric Administration (NOAA), in the period 2000-2017. A maximum cross-wavelet power close to 0.45 was obtained for the representative period of 1 year and also to periods between 3 and 4 years, associated with the positive phase of the SOI index (i.e. , La Ni?a) or with a transition to the positive phase. The evolution of the combined variability of SOI and dengue can be expressed by progressive differences in phase along the time, eventually resulting in yielding phases (i.e., La Niña-Dengue epidemic). 展开更多
关键词 Dengue Fever Cross-Wavelet Transform Analysis El Niño-Southern Oscillation Index
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A proposed model for understanding human-bacterial interactions:Space-time approach on community Escherichia coli occurrence and resistance phenomenon
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作者 Carlos R.V.Kiffer Antonio M.V.Monteiro +1 位作者 Eduardo C.G.Camargo Antonio C.C.Pignatari 《Advances in Bioscience and Biotechnology》 2013年第4期505-508,共4页
Due to ecological effect, it is expected that population exposures to antimicrobial drugs may lead to microorganisms’ modifications, occasionally leading to resistance emergence. The present review was based on previ... Due to ecological effect, it is expected that population exposures to antimicrobial drugs may lead to microorganisms’ modifications, occasionally leading to resistance emergence. The present review was based on previous empirical data and on related literature search for quantitative empirical models exploring the human-bacterial interactions. Our previous studies have shown the emergence of ciprofloxacin resistant (CIP-R) Escherichia coli significantly related to previous specific levels of ciprofloxacin consumption and to urban clusters of CIP-R E. coli. The evidence of significant spatial clustering of antimicrobial resistance (ciprofloxacin resistance E. coli) reinforces the ecological effect hypothesis as a major drive in resistance emergence. In other words, human populations submitted to a certain ciprofloxacin or quinolone usage level may affect neighbours within certain geographical areas, not necessarily due to individual antimicrobial intake, but as a driving pressure over a modified circulating E. coli population. Apparently quantitative spatial-temporal analytical frameworks may be better for understanding human-bacterial interactions based on any of their epiphenomena (antimicrobial consumption, antimicrobial resistance, geno/phenotypic characteristics). 展开更多
关键词 Escherichia coli Antimicrobial Agents MICROBIOME
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Mean and Interannual Variability of Maize and Soybean in Brazil under Global Warming Conditions
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作者 Flávio Justino Evandro Chaves Oliveira +8 位作者 Rafael de Avila Rodrigues Paulo Henrique Lopes Goncalves Paulo Jorge Oliveira Ponte Souza Frode Stordal José Marengo Thieres G.da Silva Rafael Coll Delgado Douglas da Silva Lindemann Luiz Claudio Costa 《American Journal of Climate Change》 2013年第4期237-253,共17页
Brazil is responsible for 27% of the world production of soybeans and 7% of maize. Mato Grosso and Para states in Brazil are among the largest producer. The viability to the cultivation of maize (Zea mays) and soybean... Brazil is responsible for 27% of the world production of soybeans and 7% of maize. Mato Grosso and Para states in Brazil are among the largest producer. The viability to the cultivation of maize (Zea mays) and soybeans (Glycine max), for future climate scenarios (2070-2100, GHG) is evaluated based on crop modeling (DSSAT) forced by observational data and regional climate simulations (HadRM3). The results demonstrated that a substantial reduction in the yield in particular for maize may be expected for the end of the 21st century. Distinct results are found for soybeans. By applying the A2 climate changes scenario, soybean yield rises by up top 60% assuming optimum soil treatment and no water stress. However, by analyzing the inter-annual variability of crop yields for both maize and soybean, could be demonstrated larger year-to-year fluctuations under greenhouse warming conditions as compared to current conditions, leading to very low productivity by the end of the 21st century. Therefore, these Brazilian states do not appear to be economically suitable for a future cultivation of maize and soybeans. Improved adaptation measures and soil management may however partially alleviate the negative climate change effect. 展开更多
关键词 Climate Changes SOYBEANS MAIZE
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Multi-instrument study of longitudinal wave structures for plasma bubble seeding in the equatorial ionosphere 被引量:1
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作者 H.Takahashi P.Essien +6 位作者 C.A.O.B.Figueiredo C.M.Wrasse D.Barros M.A.Abdu Y.Otsuka K.Shiokawa GuoZhu Li 《Earth and Planetary Physics》 CSCD 2021年第5期368-377,共10页
Large Scale Wave Structures(LSWS)in the equatorial ionospheric F-region were observed by measuring spatial and temporal variations within detrended total electron content(dTEC)data obtained by ground-based GNSS receiv... Large Scale Wave Structures(LSWS)in the equatorial ionospheric F-region were observed by measuring spatial and temporal variations within detrended total electron content(dTEC)data obtained by ground-based GNSS receivers over the South American continent.By using dTEC-maps,we have been able to produce,for the first-time,two-dimensional representations of LSWS.During the period from September to December,the LSWS frequently occurred starting a few hours prior to Equatorial Plasma Bubble(EPB)development.From 17 events of LSWS observed in 2014 and 2015,wave characteristics were obtained:the observed wavelengths,periods,and the phase speeds are respectively,~900 km,~41 min and~399 m/s;the waves propagated from the northeast to southeast.In some cases the front of the oscillation was meridionally aligned,extending to more than 1600 km,the first time such large extension of the wavefront has been reported.From F-layer bottom height oscillation data,measured by ionosonde,LSWS exhibit two different vertical phase propagation modes,in-phase and downward phase.The former mode indicates the presence of a polarization electric field in the F-layer bottom side;the latter suggests propagation of atmospheric gravity waves.The presence of LSWS near the solar terminator,followed by the development of EPBs,suggests that the upwelling of the F-layer bottom height produces a condition favorable to the development of Rayleigh–Taylor instability. 展开更多
关键词 IONOSPHERE Equatorial Plasma Bubble LSWS TEC
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Some Characteristics and Impacts of the Drought and Water Crisis in Southeastern Brazil during 2014 and 2015 被引量:2
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作者 Carlos A. Nobre Jose A. Marengo +2 位作者 Marcelo E. Seluchi L. Adriana Cuartas Lincoln M. Alves 《Journal of Water Resource and Protection》 2016年第2期252-262,共11页
Since the austral summer of 2014 southeastern Brazil has been experiencing one of the most severe droughts in decades. This rainfall deficiency has generated water shortages and a water crisis that have affected popul... Since the austral summer of 2014 southeastern Brazil has been experiencing one of the most severe droughts in decades. This rainfall deficiency has generated water shortages and a water crisis that have affected population and local economies in the metropolitan region of Sao Paulo, the largest megacity in South America. By January 2015, main reservoirs had reached storage levels of only 5% of their 1.3 billion m3 capacity. The meteorological causes of the drought situation were linked to changes in the regional circulation, characterized by a mid-troposphere blocking high that lasted 45 days during the summer of 2014 over southeastern Brazil, something not seen in five decades. The water crisis was aggravated by a combination of lack of rainfall and higher temperatures, the summer of 2014 being the warmest and driest over the Cantareira reservoir system since 1951. Increasing population and water consumption increased vulnerability in the region, and while human-induced warming may not have generated the atmospheric conditions behind the 2014 and 2015 summer droughts in Southeast Brazil, it is more likely that the warm temperatures have affected the severity of the drought and exacerbated the impacts on the population. 展开更多
关键词 DROUGHT Sao Paulo Water Crisis VULNERABILITY
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Assessing the Influence of Climate Extremes on Ecosystems and Human Health in Southwestern Amazon Supported by the PULSE-Brazil Platform 被引量:1
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作者 L. E. O. C. Aragão J. A. Marengo +13 位作者 P. M. Cox R. A. Betts D. Costa N. Kaye L. Alves L. T. Smith I. F. A. Cavalcanti G. Sampaio L. O. Anderson M. Horta S. Hacon V. L. Reis P. A. M. Fonseca I. F. Brown 《American Journal of Climate Change》 2016年第3期399-416,共18页
The complexity of multi-dimensional climate, environmental and human health information complicates bringing together scientists, civil society, and decision makers to provide adequate mitigation and adaptation option... The complexity of multi-dimensional climate, environmental and human health information complicates bringing together scientists, civil society, and decision makers to provide adequate mitigation and adaptation options for the consequences of global environmental change. To provide an effective pathway to conciliate (integrate) these datasets, we present PULSE-Brazil as the Platform for Understanding Long-term Sustainability of Ecosystems and human health. The overarching aim of this paper is to focus on two study cases in the Brazilian state of Acre, 1) analyzing recent socio-environmental disasters such as the impacts of droughts and consequent increases in fire detections on the incidence of respiratory diseases, and 2) evaluating the impacts of temperature increases in combination with rainfall seasonality upon the incidence of Dengue fever. Based on data available in PULSE-Brazil platform, we also aim to provide insights on the consequences of future climate variability on ecosystems and human health. Finally, we provide a discussion on the collaborative process between scientists and policymakers that defined the PULSE-Brazil platform specifications and datasets and propose a conceptual pathway for promoting the interaction between science and policy during the process of producing a tool that allows the understating of climate-relate processes. Our results clearly demonstrated that ecosystems are under increased fire risk in the future that will, in turn, affect the health of human populations. Moreover, humans are also exposed to critical Dengue fever outbreaks with the projected increase in minimum temperatures. Therefore, minimizing the impacts of these potentially ascending socio-environmental problems is the first step for adapting to a changing climate in the Amazon region. We expect that PULSE-Brazil will serve not only as a technical tool for supporting governance, management, mitigation and long-term adaptation plans for climate impacts and natural disasters, but also will take advantage of its graphical capabilities to be an instructive vehicle that facilitates information flow for societal governance. 展开更多
关键词 AMAZON DROUGHTS Human Health Fire Climate Change VULNERABILITY Adaptation Natural Hazard
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Study of Reinforcement Distribution,Adhesion between Layers,and Porosity Induced by FDM 被引量:1
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作者 Arthur Wernke Rafael dos Santos +2 位作者 Leonardo Santos Manuel Barcelos Jr Emmanuel Lima 《材料科学与工程(中英文A版)》 2021年第2期56-62,共7页
This study aims to understand the distribution of reinforcement material in the matrix,evaluate the adherence between layers,and determine the air gap between printing roads.We printed the specimen with two different ... This study aims to understand the distribution of reinforcement material in the matrix,evaluate the adherence between layers,and determine the air gap between printing roads.We printed the specimen with two different composite materials,Polylactic Acid(PLA)reinforced with acrylic particles,and another filament reinforced with short carbon fibers.For the observations of the samples,we used a Confocal Microscope.We estimated the porosity of the material by comparing the expected mass with that achieved after manufacture.By pixel count,after binarization,we found the average percentage of acrylate particulate.They showed fair distribution through the PLA matrix even after the manufacturing process.The determination of fibers alignment was made by binarization of image,together with k-means and edge detection.This combination of methods allows estimating the fiber alignment by orientation straight lines.The manufacturing process did not offer good alignment of the fibers,even with the filament initially well aligned. 展开更多
关键词 3D printing porosity in 3D printed parts 3D printed composite materials
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巴西亚马孙阿马帕州境内两湖流域人发和环境样品中的汞
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作者 Jean Remy Davée Guimar■es Anne-Hélène Fostier +6 位作者 Maria Cristina Forti José Adolfo Melfi Helena Kehrig Jane Beatriz Narvaez Mauro Olaf Malm José Francisco Krug 李春红 《AMBIO-人类环境杂志》 1999年第4期296-301,共6页
本文测定了巴西亚马孙阿马帕州两个相似湖泊中的沉积物、食鱼鱼以及湖区人发中的总汞量。这两个湖分别为:受采金矿区排放汞影响的Duas Boeas湖(DBL)和其北部15km处原始的Praeudba湖(PL)。在DBL沉积物中,纵剖面汞的含量范围为汞污染的发... 本文测定了巴西亚马孙阿马帕州两个相似湖泊中的沉积物、食鱼鱼以及湖区人发中的总汞量。这两个湖分别为:受采金矿区排放汞影响的Duas Boeas湖(DBL)和其北部15km处原始的Praeudba湖(PL)。在DBL沉积物中,纵剖面汞的含量范围为汞污染的发展进程提供了清晰的证据,并且发现DBL区鱼体和人发中汞的含量远远高于PL区。沉积物中的^(203)Hg甲基化速率及鱼体中甲基汞的比率,都显示出汞在两湖中具有较高的生物有效性。当地成年人每天平均食鱼量约为200g,而在DBL湖,95%的鱼样(样品数N=40)超过15ng Hg/g这一安全限。Hg在人发中平均含量为28μg/g(N=15),已在一个可引发神经中毒效应的水平上。然而,在未受污染的PL湖,汞含量也较高,在这里67%~100%(N=34)鱼类的汞含量超过安全限,87%的人发样品(N=15)高于10ng Ha/g。建议这两个区域的儿童和孕妇应吃非食鱼性的鱼类和/或小鱼类,对阿马帕沿海平原的其他区域也应开展汞含量水平的调查。 展开更多
关键词 巴亚 亚马孙阿马帕州 湖泊沉积物 人发 汞污染
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Satellite Images Applied to Assess the Influence of Amazon River Seasonal Dynamic on the Floodplain Lake Morphology
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作者 Andreia M.S.Franca Teresa G.Florenzano Evlyn M.L.M.Novo 《Open Journal of Ecology》 2014年第13期820-831,共12页
The objective of this study is to assess the influence of the Amazon River seasonal dynamic on floodplain lake morphology. The study area includes the Amazon River floodplain reach encompassed by the Madeira and Tapaj... The objective of this study is to assess the influence of the Amazon River seasonal dynamic on floodplain lake morphology. The study area includes the Amazon River floodplain reach encompassed by the Madeira and Tapajós River confluences. Products from the Global Rain Forest Mapping (GRFM) and Moderate Resolution Imaging Spectroradiometer (MODIS) were used to derive variables such as lake size, shape and number. The main steps in the research were: data base implementation, legend definition, image processing (merge, segmentation, classification and edition), morphological mapping and quantitative assessment. Four classes of lacustrine morphology were defined in this study: circular/elliptical, elongated, composite, and dendritic. The result showed that 1) the lake class increased 18.38% from the low- to high-water period;2) there was a reduction in the total number of lakes from low to high water;3) the most common lake type was the circular/elliptical;and 4) better results were obtained integrating SAR and optical sensors. 展开更多
关键词 Amazon River Floodplain Seasonal Dynamic Morphological Lakes Remote Sensing SAR-JERS-1/GRFM MOD09-TERRA
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An Alternative Manifold for Cosmology Using Seifert Fibered and Hyperbolic Spaces
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作者 Maria E.Mejía Reinaldo R.Rosa 《Applied Mathematics》 2014年第6期1013-1028,共16页
We propose a model with 3-dimensional spatial sections, constructed from hyperbolic cusp space glued to Seifert manifolds which are in this case homology spheres. The topological part of this research is based on Thur... We propose a model with 3-dimensional spatial sections, constructed from hyperbolic cusp space glued to Seifert manifolds which are in this case homology spheres. The topological part of this research is based on Thurston’s conjecture which states that any 3-dimensional manifold has a canonical decomposition into parts, each of which has a particular geometric structure. In our case, each part is either a Seifert fibered or a cusp hyperbolic space. In our construction we remove tubular neighbourhoods of singular orbits in areas of Seifert fibered manifolds using a splice operation and replace each with a cusp hyperbolic space. We thus achieve elimination of all singularities, which appear in the standard-like cosmological models, replacing them by “a torus to infinity”. From this construction, we propose an alternative manifold for cosmology with finite volume and without Friedmann-like singularities. This manifold was used for calculating coupling constants. Obtaining in this way a theoretical explanation for fundamental forces is at least in the sense of the hierarchy. 展开更多
关键词 TOPOLOGY COSMOLOGY Thurston’s Theory Singularity-Free
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Atacama Field Campaign: laboratory and in-situ measurements for remote sensing applications
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作者 Cristian Mattar Andrés Santamaría-Artigas +3 位作者 Flavio Ponzoni Cibele T.Pinto Carolina Barrientos Glynn Hulley 《International Journal of Digital Earth》 SCIE EI 2019年第1期43-61,共19页
This work presents the preliminary results of the first field calibration campaign performed in the Atacama Desert,Chile,between the 18 and 22 August 2014,called the Atacama Field Campaign(ATAFIC 2014).In situ measure... This work presents the preliminary results of the first field calibration campaign performed in the Atacama Desert,Chile,between the 18 and 22 August 2014,called the Atacama Field Campaign(ATAFIC 2014).In situ measurements were performed in order to spectrally characterize the surface reflectance spectra between 0.3 and 2.5μm,radiometric temperature(8.0–14.0μm)and atmospheric measurements.A soil sample was collected and analyzed using Fourier Transform Infrared Spectroscopy and X-Ray Diffraction techniques to characterize the surface reflectance spectra and mineralogical composition,respectively.ASTER land surface emissivity in addition to GOES,MODIS and Landsat-8 land surface temperature(LST)were also used.Results showed that the spectral features of the Atacama soil and the characteristics of this geographical zone,which is featured as the most hyper-arid and cloudless place in the world,make this area a potential target for surface reflectance characterization.Day and night LST comparison between field and remote sensing data are lower than 2 K and the Root Mean Square Error for land surface emissivity is close to 2%.This work opens the possibilities to consider the Atacama Desert as a reference target for calibration and validation activities for earth observation missions’purposes. 展开更多
关键词 ATACAMA SPECTRORADIOMETRY EMISSIVITY temperature surface reflectance
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