Traits of leaf anatomy of Croton lanjouwensis Jablonsky (Euphorbiaceae) in different strata of the plant.

The distribution of C. lanjouwensis, commonly known as "Dima", is restricted to the Brazilian State of Amazonas. The species is a common tree in secondary forests. In the poster, the leaf anatomy of this species is described for leaves of different strata of a plant growing in an 11 year-old secondary forest of approx. 20 m in height, in order to study the phenotypic plasticitty of the leaf as a whole and of single anatomic structures

Conduction States with Vanishing Dimerization in Pt Nanowires on Ge(001) Observed with Scanning Tunneling Microscopy

The low-energy electronic properties of one-dimensional nanowires formed by Pt atoms on Ge(001) are studied with scanning tunneling microscopy down to the millivolt-regime. The chain structure exhibits various dimerized elements at high tunneling bias, indicative of a substrate bonding origin rather than a charge density wave. Unexpectedly, this dimerization becomes vanishingly small when imaging energy windows close to the Fermi level with adequately low tunneling currents. Evenly spaced nanowire atoms emerge which are found to represent conduction states. Implications for the metallicity of the chains are discussed.Comment: 4 pages, 4 figure

Analysis of growth form types and floristic composition due to past disturbance and plantation management in the SHIFT experimental area.

Em terra firme próximo a Manaus, Amazonas, está sendo executado um experimento com sistemas de policultivo de plantas úteis, estabelecido em um plantio de seringueira abandonado. São testadas diferentes combinações de plantas úteis em 90 parcelas e 5 blocos.bitstream/item/180857/1/Recuperacao-47-61.pd

Electronic structure of nanoscale iron oxide particles measured by scanning tunneling and photoelectron spectroscopies

We have investigated the electronic structure of nano-sized iron oxide by scanning tunnelling microscopy (STM) and spectroscopy (STS) as well as by photoelectron spectroscopy. Nano particles were produced by thermal treatment of Ferritin molecules containing a self-assembled core of iron oxide. Depending on the thermal treatment we were able to prepare different phases of iron oxide nanoparticles resembling gamma-Fe2O3, alpha-Fe2O3, and a phase which apparently contains both gamma-Fe2O3 and alpha-Fe2O3. Changes to the electronic structure of these materials were studied under reducing conditions. We show that the surface band gap of the electronic excitation spectrum can differ from that of bulk material and is dominated by surface effects.Comment: REVTeX, 6 pages, 10 figures, submitted to PR

Morphological traits and ecological behavior of selected secondary forest tree species in the central Amazon.

The aim of the study is to detect causal links between the parameters measured and the ecological behavior of the species observed in the field, as a contribution to an autecological description of the secondaty forest tree species, in the Manaus-AM (Brasil). The results show some characteristics which can be interpreted as "functional traits" of certain types of secondary forest plants, e.g. the plant biomass of the species examined is negatively correlated with leaf sizes and with the percentage of leaf biomass in relation to total biomass

Indicator value of anthropogenic vegetation in the Amazon.

An evaluation of the effects of the experimental variants on the useful plants and the plantion systems calls for knlwledge of the extremely complex interaction between useful plants and spontaneous vegetation and of other environmental factors. A preliminary analysis of the spontaneous vegetation revealed that species compostion and structural traits of the vegetation were closely linked to the pre-use of the sites and recent management measure. In this study the data sets and some of the results of theira analysis to date are presented and discussed

Indicator value of anthropogenic vegetation in the Amazon.

The main objective is to device a system whereby individual species of vascular plants and structural traits of vegetation can serve as indicators of site conditions, especially for the intensity and type of pre-use of sites (=disturbance) and hence with that for the actual suitability of the sites for agriculture

Indicator value of anthropogenic vegetation in the Amazon.

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