Relevance of ion-induced nucleation of sulfuric acid and water in the lower troposphere over the boreal forest at northern latitudes     

M. Boy  J. Kazil  E.R. Lovejoy  A. Guenther  M. Kulmala 《Atmospheric Research》2008,90(2-4):151-ICNAA07

The relevance of ion-induced nucleation of sulfuric acid and water (IINSW) in the troposphere over the boreal forest at northern latitudes is investigated by combining two existing and previously published models (MALTE — model to predict new aerosol formation in the lower troposphere; PARNUC — a parameterized steady-state model of neutral and ion-induced nucleation of sulfuric acid and water for atmospheric conditions). Simulations were performed for 4 days with observed new particle formation at ground level by using input data from the SMEAR II station in Hyytiälä, Finland. The selected days were chosen to cover a wide range of values of the parameters most relevant for IINSW. The results showed that ion-induced nucleation of sulfuric acid and water can contribute up to 15% to the total amount of newly formed particles in the size range of 3–10 nm inside the mixed layer at the Hyytiälä site. The importance of IINSW seemed to increase in the free troposphere above the boundary layer, however, lack of measurements in the vertical structure of the input parameters suggest that the model results are burdened with high uncertainties.  相似文献   

Metamorphic path constrained by metapelitic rocks from the inner Aiuruoca-Andrelândia nappe, south of the São Francisco craton, SE Brazil     

Luciana Pascarelli Santos  Mario da Costa Campos Neto  Carlos Henrique Grohmann 《Journal of South American Earth Sciences》2004,16(8):125

A Nappe system south to southwest of the São Francisco Craton represents the southern extension of the Brasília belt and describes an inverted metamorphic pile of greenschist facies toward amphibolite facies. The Aiuruoca-Andrelândia nappe is one of the nappes of this system. The hind portion of the Aiuruoca-Andrelândia nappe, south of Caxambu and Aiuruoca (MG), consists of a structural-metamorphic domain transported toward the E-NE. There is a metamorphic transition, from the kyanite zone to kyanite and sillimanite coexistence, until the sillimanite zone. Metapelitic rocks preserve high-pressure parageneses (Rt–Ky–Grt–Ms–Bt–Pl–Qtz) and contain retrograde eclogitic rocks. Sil–Pl–Qtz coronitic intergrowths around garnets are common decompressive textures. Kyanite schists register the P_max of 11 kbar at 660 °C and define a decompressive path until 6–7.5 kbar at 650 °C. These P–T conditions represent the equilibrium in S₂ schistosity (amphibolite facies) and the beginning of the cooling path in the Ky–Sil transition. The decompressive path suggests an extrusional process, immediately after burying at about 60 km. Exhumation controlled by convergent events, related to the São Francisco Plate subduction and tectonic erosion, took these units, isothermally, to higher levels (20–33 km). Later, the metamorphic path shifted toward near-isobaric cooling.  相似文献   

Ar/Ar geochronology of gold mineralization in Brasiliano strike-slip shear zones in the Borborema province, NE Brazil     

Mrio Neto C. Araújo  Paulo M. Vasconcelos  Fernando C. Alves da Silva  Emanuel F. Jardim de S  Jaziel M. S 《Journal of South American Earth Sciences》2005,19(4):445-460

⁴⁰Ar/³⁹Ar geochronology of muscovite and biotite grains genetically related to gold and Be–Ta–Li pegmatites from the Seridó Belt (Borborema province, NE Brazil) yield well-defined, reliable plateau ages. This information, combined with data about paragenetic and field relationships, reveals Cambro-Ordovician mineralization ages (520 and 500–506 Ma) for the orogenic gold deposits in the Seridó Belt. Biotite ages of 525±2 Ma, which represent the mean weighted results of the incremental heating analysis of six biotite single crystals, record the time of pegmatite emplacement and reactivation of Brasiliano/Pan-African strike-slip shear zones. These results, along with previous structural evolution studies, suggest that shear zones formed during the Brasiliano/Pan-African event were reactivated in the Upper Cambrian–Lower Ordovician. Mineralization occurs late in the history of the orogen.  相似文献   

Resistivity and ground-penetrating radar images of fractures in a crystalline aquifer: a case study in Caiçara farm—NE Brazil     

Carlos Csar Nascimento da Silva  Walter Eugênio de Medeiros  Emanuel Ferraz Jardim de S  Pedro Xavier Neto 《Journal of Applied Geophysics》2004,56(4):295-307

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Geosteranes: Identification and synthesis of a novel series of 3-substituted steranes     

JosA. D. Lopes  Eugênio V. Santos Neto  Mrcio R. Mello  Francisco De A.M. Reis 《Organic Geochemistry》1997,26(11-12)

A novel series of 3-alkyl and 3-carboxyalkyl-5β(H)-steranes 7–10 along with a full homologous series of carboxyalkyl-sterane (C₁ to C₆) 4–6 with 3α(H)5α(H) configuration have been identified in marine-evaporitic oils from Fazenda Belém, Potiguar Basin (Brazil) on the basis of mass spectral interpretation. The synthesis of enantiomerically pure 3α-alkyl-5β(H)-cholestane and 3β-alkyl-5α(H)-cholestane standards and their coinjection with petroleum fractions confirmed the structural assignments.  相似文献   

Modeling the impacts of climate change on China''s agriculture   总被引：1，自引：0，他引：1  

LIU Hui~  LI Xiu-bin~  Guenther Fischer~  SUN Lai-xiang~ 《地理学报(英文版)》2001,11(2):149-160

1 Introduction Since recognition of the potential climate change [IPPC, 1990], efforts have been made to estimate the economic impacts of projected changes in climate on important sectors, such as agriculture, forestry and ecosystem, coastal zones and fisheries, water resource, and energy development. Although several sectors have been studied, none have received more attention than agriculture. Countrywide economic analysis has been completed for the United States[1-4], India[5] and Brazil…  相似文献   

Extended saturated and monoaromatic tricyclic terpenoid carboxylic acids found in Tasmanian tasmanite     

D.A. Azevedo  F.R.Aquino Neto  B.R.T. Simoneit   《Organic Geochemistry》1994,22(6)

A series of tricyclic terpenoid carboxylic acids (C₂₀–C₄₀) was found in the acidic fraction of Tasmanian tasmanite bitumen, occurring as a mixture of stereoisomers with mainly the 13β(H), 14α(H)-and 13α(H),14α(H)-configurations. These dominant acidic tricyclic constituents have the same carbon skeleton as the ubiquitous tricyclic terpane biomarkers. A novel series of ring-C monoaromatic tricyclic terpenoid carboxylic acids was also characterized. The series ranges from C₁₉ to C₃₉ and is the acidic counterpart of the recently described series of monoaromatic tricyclic terpanes.  相似文献   

Vegetation evolution by ecological succession as a potential bioindicator of landslides relative age in Southwestern Mediterranean region     

Lopes  Luís Filipe  Oliveira  Sérgio Cruz  Neto  Carlos  Zêzere  José Luís 《Natural Hazards》2020,103(1):599-622

Natural Hazards - Landslides have a direct impact in the ecosystems dynamics being considered one of the main vegetation perturbation processes. Our objective is to determine the relation between...  相似文献   

A Mini‐Review of E‐Waste Management in Brazil: Perspectives and Challenges     

Jos Francisco de Oliveira Neto  Maisa Mendona Silva  Simone Machado Santos 《洁净——土壤、空气、水》2019,47(9)

The accelerated production and replacement of new electrical and electronic equipment demonstrates a tendency for the proportional increase in the generation of e‐waste. Developing countries experience similar social and environmental consequences from this trend, which compounds the other challenges associated with the already poor solid waste management in these regions. Moreover, the dangerous composition of some e‐waste amplifies the problems related to managing these materials. This mini‐review presents a brief overview of e‐waste management in Brazil, including technical aspects, scientific studies, and the challenges ahead. With the Brazilian National Policy of Solid Waste already in place, technical and scientific studies endorse measures that range from incorporating the informal recycling sector into the e‐waste management sector to encouraging the expansion of the recycling industry. All such actions, combined with an intensified commitment of electronic equipment manufacturers to reverse logistics, can improve e‐waste management in Brazil.  相似文献   

The specific entropy of elliptical galaxies: an explanation for profile-shape distance indicators?     

G. B. Lima Neto  D. Gerbal  I. Márquez 《Monthly notices of the Royal Astronomical Society》1999,309(2):481-495

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