检索结果-南通市图书馆

Lithic soils in the semi-arid region of Brazil:edaphic characterization and susceptibility to erosion

Journal of Arid Land 2022年第1期14卷 56-69页

作者： Carlos R PINHEIRO JUNIOR Conan A sALVADOR Tiago R TAVAREs Marcel C ABREU hugo s fagundes Wilk s ALMEIDA Eduardo C sILVA NETO Lúcia H C ANJOs Marcos G PEREIRA Federal Rural University of Rio de Janeiro(UFRRJ) Department of SoilsSeropédicaRio de Janeiro 23890Brazil Center for Nuclear Energy in Agriculture(CENA) University of São Paulo(USP)PiracicabaSão Paulo 13416Brazil Federal Institute of Education Science and Technology of Rondônia(IFRO)Rural ZoneAriquemesRondônia 78930Brazil

soils(Leptosols or Epileptic Regosols)with lithic contact at a depth of 50 cm occupy almost 20%of the Brazilian semi-arid *** lithic soils are susceptible to erosion due to faster saturation of water-holding capacity during rainfall,which accelerates the beginning of ***,erosion traits of lithic soils in the semi-arid region of Brazil are less *** aim of this study was to characterize the soil and landscape attributes in areas with Neossolos Litólicos(Entisols)in the Caatinga biome to identify region of high susceptibility to *** showed that the soils were characterized by a sandy texture,soil structure with poor development and low content of organic *** attributes increase susceptibility to erosion and reduce water storage capacity,especially in the states of Cearáand *** these states,the content of rock fragments in the soil reaches 790 g/*** contents of silt and fine sand,high silt/clay ratio,predominance of Leptosols and strong rainfall erosivity were observed in Piauíand northwestern Ceará.A very high degree of water erosion was observed in the states of Pernambuco and Paraí*** the low degree of erosion observed in the state of Bahia,it is highly susceptible to erosion due to the predominance of very shallow soils,rugged relief and high values of rainfall *** vulnerability was observed in the state of Alagoas because of its more smoothed relief,greater effective soil depth,thicker A horizon of soil and lower rainfall *** general,the characteristics that intensify the susceptibility to erosion in the Caatinga biome are those soil structures with poor development or without aggregation,low contents of organic carbon,high contents of silt and fine sand,high values of silt/clay ratio and rugged relief in some *** study collected information contributing to a better characterization of soils with lithic contact in the semi-arid region of *** addition,regions with

关键词： Caatinga biome drylands erosive processes leptosols soil degradation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Feasibility of performing the 3-minute step test with remote supervision in children and adolescents with cystic fibrosis: A comparative study

引用

Pediatric Investigation 2024年第2期8卷 83-90页

作者： Fernanda Maria Vendrusculo Gisele Apolinario da Costa Maria Amelia Bagatini Brenda Maria Henrique Maia Lemes Carolina Aguiar Faria Larissa Carvalhaes de Oliveira Evanirso da silva Aquino Marcio Vinicius fagundes Donadio Laboratory of Pediatric Physical Activity Infant CenterPontificia Universidade Catolica do Rio Grande do Sul(PUCRS)Porto AlegreBrazil Hospital Infantil Joao Paulo II-Fundacao Hospitalar do Estado de Minas Gerais(FHEMIG) Belo HorizonteBrazil Departament of Physiotherapy Pontificia Universidade Catolica de Minas Gerais(PUCMG)-Campus BetimBetimBrazil Department of Physiotherapy Faculty of Medicine and Health SciencesUniversitat Internacional de Catalunya(UIC)BarcelonaSpain

Importance:The 3-min step test is a simple option to monitor submaximal exercise capacity,although its use via remote video monitoring has not been investigated in children with cystic fibrosis(CF).Objective:This study aimed to assess the feasibility and reproducibility of performing the 3-min step test with remote ***:A cross-sectional study including CF patients(6-18 years)from two CF services were ***,anthropometric,clinical,and lung function data were collected and two 3-min step tests were performed:(i)in-person supervision,and(ii)remotely supervised by video *** and after the tests,heart rate(HR),oxygen saturation(spO2),and the Borg score for dyspnea and lower limb fatigue were ***:Twenty-three patients(10.7±3.7 years)with a mean FEV1 of 89.5%±23.2%were *** were no significant differences between tests,with mean differences(95%confidence intervals)in final HR of-3.3(-8.9,2.4),change in HR of-1.9(-6.1,2.1),final spO2 of 0.3(-0.4,1.0),and final dyspnea of 0.1(-0.8,0.9).The intraclass correlation coefficient was 0.852(final HR),0.762(final spO2),and 0.775(final lower limb fatigue).significant and moderate correlations were found between tests for final HR(r=0.75),change in HR(r=0.61),and final spO2(r=0.61).The Bland-Altman analysis showed a mean difference in final spO2 between tests of 0.3%(limit of agreement-3.0%,3.5%).Interpretation:Physiological responses between tests were similar,indicating it was feasible to perform the 3-min step test with remote supervision in CF children.

关键词： Children Cystic fibrosis Exercise test Telehealth

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Modeling uncertainties of reservoir flushing simulations

引用

International Journal of sediment Research 2023年第5期38卷 698-710页

作者： Camila Bergmann Goulart Tobias Bleninger hugo de Oliveira fagundes Fernando Mainardi Fan Department of Environmental Engineering Federal University of Parana Institute of Hydraulic Research Federal University of Rio Grande do Sul

Every dam or barrage construction affects the watercourse and the retention of sediment that previously was carried by the river, which can lead to siltation of the reservoir and obstruction of water intakes over time, reducing their capacities. However, the information available regarding the effect of sediment and drawdown parameters, sediment management at reservoirs, as well as different equational approaches,is scarce. The current research aims to evaluate the effect of parameters associated with numerical modeling of sediment management in reservoirs considering scenarios with different drawdowns,transport equations, sediment size distributions, and thickness of the initial sediment layer. The case study of the Aimore s Hydropower Plant(HPP) is used, applying the Delft3D-FLOW model for twodimensional modeling. All parameters influenced the volume of mobilized sediment, among which the initial layer thickness was the parameter that resulted in the greatest changes in simulated results. In general, the results show that the uncertainties in the input parameters outweigh the uncertainties between the techniques, which found large variations in results when evaluating the use of different transport equations. These results indicate the importance of proper estimation of model parameters for predicting effects with accuracy and the need for such studies before planning and management operations are evaluated to avoid environmental harm and energy waste.

关键词： Reservoir sedimentation sediment transport modeling Flushing sediment management

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Thermal and photoperiodic requirements of the seedling stage of three tropical forest species

引用

Journal of Forestry Research 2023年第1期34卷 209-220页

作者： Fabrina Bolzan Martins Mábele de Cássia Ferreira Flávia Fernanda Azevedo fagundes Gabriel Wilson Lorena Florêncio Natural Resource Institute Federal University of ItajubáItajubáMinas Gerais 37500-903Brazil

Air temperature and photoperiod play an important role in the seedling development for tropical forest *** variables are sensitive to climate,and so evaluating thermal and photoperiodic effects on seedling development is fundamental,especially for climate change *** to quantify thermal time and the energy required for plants to reach a development stage include air temperature and cardinal *** photoperiod will also affect physiological reactions of a plant and thus its *** we evaluated the six thermal time methods widely used to compute thermal requirement,and identified the influence of the photoperiod from the 2015 and2016 growing seasons and 12 sowing dates in Itajubá,Minas Gerais state,Brazil,on seedling development of three native tropical forest species Psidium guajava L.(Myrtaceae),Citharexylum myrianthum Cham.(Verbenaceae),and Bixa orellana L.(Bixaceae).The method used to quantify thermal time influenced the analytical results of seedling development;the one that considered three cardinal temperatures and compared them with the mean air temperature(Method5)performed better in computing thermal *** influence of photoperiod on seedling development was inconclusive for the three species,but all three developed better in mild temperatures(between 13.3℃and 26.9℃)with a photoperiod shorter than 13 h.

关键词： Phyllochron Thermal time Day length seedling stage Phenology

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Hydrological variability and long-term floristic-structural modifications in different habitats of a tropical semi-deciduous forest

引用

Journal of Forestry Research 2022年第3期33卷 801-811页

作者： Alisson Borges Miranda santos Vinicius Andrade Maia Cléber Rodrigo de souza Natália de Aguiar-Campos Aurélio de Jesus Rodrigues Pais Wilder Bento da silva Nathalle Cristine Alencar fagundes Jean Daniel Morel Rubens Manoel dos santos Department of Forestry sciences Federal University of LavrasCampus UniversitárioC.P.3037LavrasBrazil Faculty of Environmental Engineering and Natural Resources Zambeze UniversityChimoioC.P.2400Mozambique Biological sciences Universidade do Estado de Minas GeraisUnidade ItuiutabaAv.Antônio Carlos 6627Ituiutaba31270-901Brazil Department of Biology Federal University of LavrasUniversity campusC.P.3037Lavras37200-000Brazil

shifts in hydrological regimes alter river flow rates and flood pulses, decrease environmental heterogeneity and the floristic-structural complexity of associated plant communities. We tested the hypothesis that drought events affect plant community composition and structure at a small-scale within a riparian fragment towards a reduction in floristic-structural complexity. The tree community was sampled in three habitats (wet, transitional and dry) and monitored in seven inventories carried out between 1991 and 2018. Hydrological variations were evaluated through annual rainfalls, river flow rates and water level data. The species richness and the detrended correspondence analysis axes were used to characterise the temporal modifications in floristic composition. Community structure was described in terms of biomass: accumulated, growth of survivors, mortality and recruitment. Generalised linear mixed models were fitted to evaluate the effects of time and environment in community. It was concluded that the climate has become drier in recent years due to declining precipitation that has affected flow rates and water levels. The floristic-structural complexity of the study fragment was maintained during the monitoring period. However, prolonged and extreme drought events displayed the potential to impact floristic-structural patterns.

关键词： Forest dynamics Climate changes semi-deciduous seasonal forest Temporal change Functioning communities

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Neumann Boundary Conditions Inhibiting ssB in Coleman-Weinberg Mechanism

引用

Communications in Theoretical Physics 2010年第12期54卷 1071-1074页

作者： F.N.fagundes R.O.Francisco B.B.Dilem J.A.Nogueira Universidade Federal do Espírito santo

如果有限区域的长度是足够小的，在这个工作，我们证明同类的 Neumann 边界条件为自发的对称在分级的 electrodynamics 碎禁止 ColemanWeinberg 机制(= e2 M ? 1， M 在哪儿是分级的地的团，由 ColemanWeinberg 机制产生了) 。

关键词：平衡机制诺伊曼边界条件温伯格 Neumann边界条件单边带自发对称破缺电动力学有限区域

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Continuous positive airway pressure acutely increases exercise duration in children with severe therapy-resistant asthma:a randomized crossover trial

引用

World Journal of Pediatrics 2021年第2期17卷 189-196页

作者： Claudia silva schindel Daniele schiwe Joao Paulo Heinzmann-Filho Natalia Evangelista Campos Paulo Marcio Pitrez Marcio Vinicius fagundes Donadio Laboratory of Pediatric Physical Activity Centro Infant.Pontiffcia Universidade Catolica do Rio Grande do Sul(PUCRS)Av.Ipiranga6690.2°andarPorto AlegreRS CEP 90610-000.Brazil Hospital Moinhos de Vento Porto AlegreBrazil and Centro InfantPontiffcia Universidade Catolica do Rio Grande do Sul(PUCRS)Porto Alegre.Brazil

Background Lower exercise tolerance is an important component of asthma and the possible effects of non-invasive ven-tilation on exercise capacity in individuals with severe therapy-resistant asthma(sTRA)are *** study aimed to evaluate the immediate effect of continuous positive airway pressure(CPAP)on exercise tolerance in children with *** We performed a controlled,randomized,crossover clinical trial including subjects aged 6 to 18 years old diagnosed with ***,anthropometric and lung function data were *** participants in the intervention group(IG)used CPAP(PEEP 10cmH2O and FiO20.21)for a period of 40 *** in the control group(CG)used CPAP with mini-mum PEEP at 1 cmH20 also for 40 ***,subjects from both groups underwent cardiopulmonary exercise testing(CPET).After a 15-day washout period,on a subsequent visit,subjects participated in the opposite group to the initial *** Thirteen subjects with a mean age of 12.30±1.7 years were *** variables of peak expiratory flow(PEF)and forced expiratory volume in the first second(FEV1)before using CPAP and after performing CPET did not show sig-nificant *** CPET results,there was no significant difference(P=0.59)between groups at peak exercise for oxygen consumption—VO2(CG:33.4±6.3 and IG:34.5±5.9,mL kg^(-1)min^(-1)).However,the IG(12.4±2.1)presented a total test time(min)significantly(P=0.01)longer than the CG(11.5±1.3).Conclusion The results suggest that the use of CPAP before physical exercise increases exercise duration in children and adolescents with sTRA.

关键词： Asthma Non-invasive ventilation Oxygen consumption Exercise test Exercise tolerance Exercise-induced bronchospasm

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

阿塞洛米塔尔图巴朗钢铁集团火花发射光谱法优化氮的分析

引用

冶金分析 2012年第7期32卷 25-31页

作者： fagundes Laura DIEGUEZ Ana Carolina 阿塞洛米塔尔图巴朗钢铁集团

近年来,钢铁行业需求量快速上升,竞争也变得更加激烈。为了得到性能可靠的产品,钢铁车间在生产工艺方面需要进一步严格控制好产品的生产规格。在这种背景下,为了严格控制好生产工艺的密封性并保证产品所期望的特性(尤其是其韧性和机械... 详细信息

近年来,钢铁行业需求量快速上升,竞争也变得更加激烈。为了得到性能可靠的产品,钢铁车间在生产工艺方面需要进一步严格控制好产品的生产规格。在这种背景下,为了严格控制好生产工艺的密封性并保证产品所期望的特性(尤其是其韧性和机械加工性方面),精确地进行氮的分析必不可少。在过去几年中,经典燃烧技术(CC)已广泛应用于鉴定钢中的碳、硫和氮元素。而火花发射法因其性能改进、耗材成本(燃烧技术方面)降低以及在分析时间缩短等方面的优势,也在氮分析方面得到了应用,并且应用越来越广泛。本项研究的目的在于通过火花发射光谱仪(OEs)对氮分析进行优化。研究是在巴西塞拉的阿塞洛米塔尔图巴朗钢铁集团的化学分析实验室进行,利用DMAIC方法学(一种用于改进生产工艺质量的研究方法)[1],对潜在的影响因素(包括漂移、样品和周期)进行了分析,并确定和优化了影响氮分析精度的根本原因。在实施该计划后,对结果的精度(基于内标物的标准偏差)和准确性(通过与OE认证的参考物质和力可交叉核验结果进行比较)进行了评估。在本研究项目之前,通过光发射法测得的氮元素的标准偏差高达0.004 0%。阿塞洛米塔尔图巴朗钢铁集团利用光谱仪完成所有的研究计划后,试验表明,其测定标准偏差低达0.000 5%,充分展现了该技术的潜力。本研究对这一标准偏差进行了监测,频率为每周一次,监测期为3个月。结果发现,该标准偏差在0.000 3%到0.000 5%之间波动,表明稳定性较好。由此可见,火花发射光谱技术是氮分析的一种较有前途的方法。

关键词：光发射氮分析钢铁经典燃烧

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

stepped machine learning for the development of mineral models: Concepts and applications in the pre-salt reservoir carbonate rocks

引用

能源与人工智能(英文) 2021年第1期3卷 167-179页

作者： Lucas Abreu Blanes de Oliveira Luiz Felipe Niedermaier Custodio Thais Bortotti fagundes Carina Ulsen Cleyton de Carvalho Carneiro Petrobras–Petroleo Brasileiro s.A. Avenida Henrique Valadares 28CentroRio de Janeiro20231-030 Rio de JaneiroBrazil Universidade de sao Paulo USPEscola PolitecnicaPraça Narciso de AndradeVila MathiasSantosSão Paulo 11013-560Brazil

Understanding rock mineralogy is essential for formation evaluation,improving the calculation of porosity and hydrocarbon *** primary method to obtain the mineralogy from a well is by applying a model to the geochemical tool’s chemical ***,creating a mineralogical model presents challenges such as the minerals’chemical composition and the decision to include a mineral in the *** traditional application of machine learning can make mineral models less realistic since conventional training is developed based on a set of minerals with different occurrences,lowering some minerals’*** present research proposes the stepped machine learning(sML),a stepped way to use machine learning to create a mineralogical model from chemical and mineralogical data.A database was assembled with the elemental concentration obtained with XRF analyses and the mineral concentrations obtained with XRD *** chemical elements were Al,Ca,Fe,K,Mg,Mn,Na,si,and *** minerals were calcite,dolomite,quartz,clays,K-feldspar,plagioclase,and *** algorithms were tested:MLP,GAN,Random Forest,and XGBoost,with XGBoost showing the best *** was applied,where a mineral model results are used to train a subsequent *** allowed for a significant improvement in some models,notably to clays with an increase in R 2 from 0.597 to 0.853,quartz an increase from 0.673 to 0.869,and calcite,from 0.758 to 0.862.A decrease in the mean squared error of these minerals’models was also *** model was applied to the geochemical logs from three wells drilled in the Brazilian pre-salt,and the results were compared with XRD *** sML model was able to honor the mineral concentrations for different *** is demonstrated that the integration between machine learning tools and geological knowledge in sML was crucial for creating a representative mineralogical model.

关键词： minerals quartz reservoir

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

seed size as Key Factor in Germination and seedling Development of Copaifera langsdorffii(Fabaceae)

引用

American Journal of Plant sciences 2014年第17期5卷 2566-2573页

作者： Matheus Lopes souza Marcilio fagundes Laboratorio de Biologia da Conservacao Universidade Estadual de Montes ClarosMontes ClarosBrasil Laboratorio de Fisiologia Vegetal Universidade Federal de Minas GeraisBelo HorizonteBrasil

seed size is a plastic trait of the plants that directly affect seed germination and seedling recruitment. This study aimed to investigate the relationship between seed size, seed germinability and seedling performance of Copaifera langsdorffii by testing four hypotheses: 1) larger seeds have higher germination percentage;2) smaller seeds require less time to germinate and for initial development of the seedlings;3) larger seeds produce more vigorous seedlings and 4) seed size negatively affects seedling root/shoot ratio. In 2011, we selected 30 individuals of C. langsdorffii from which 300 seeds were randomly collected in the plant canopy. All these seeds were weighted and placed in germination tray using vermiculite as substrate. seed germinability and initial development of seedlings were monitored daily until cotyledons fell. small seeds have higher germination percentage and germinate faster when compared to large seeds. Nonetheless, seedlings originated from larger seeds have longer development times, resulting in more vigorous seedlings. In addition, seedlings originating from small seeds allocate proportionally greater amount of resources to roots when compared to larger seeds. The fact that small seeds have higher germination percentage and faster germination favors the colonization of transient habitats. However, larger seeds produce more vigorous seedlings, favoring the seedling establishment in more stable habitats. Thus, we argue that high variability in seed size of C. langsdorffii favors its widespread geographic distribution.

关键词： Community Organization Plant Distribution seed Biometry seed Reserves seedling Vigor

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：