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Satellite monitoring of land-use and land-cover changes in northern Togo protected areas

Journal of Forestry Research 2014年第2期25卷 385-392页

作者： Fousseni Folega Chun-yu Zhang Xiu-hai Zhao Kperkouma Wala Komlan Batawila Hua-guo Huang Marra Dourma Koffi Akpagana The Key Laboratory for Silviculture and Conservation of Ministry of Education Beijing Forestry University Université de Lomé Laboratoire de botanique et écologie végétaleFaculté des sciences

Remote-sensing data for protected areas in northern Togo, obtained in three different years （2007, 2000, and 1987）, were used to assess and map changes in land cover and land use for this drought prone zone. The normalized difference vegetation index （NDVI） was applied to the images to map changes in vegetation. An unsupervised classification, followed by classes recoding, filtering, identifications, area computing and post-classification process were applied to the composite of the three years of NDVI images. Maximum likelihood classification was applied to the 2007 image （ETM＋2007） using a supervised classification process. Seven vegetation classes were defined from training data sets. The seven classes included the following biomes： riparian forest, dry forest, flooded vegetation, wooded savanna, fallows, parkland, and water. For these classes, the overall accuracy and the overall kappa statistic for the classi- fied map were 72.5% and 0.67, respectively. Data analyses indicated a great change in land resources; especially between 1987 and 2000 proba- bly due to the impact of democratization process social, economic, and political disorder from 1990. Wide-scale loss of vegetation occurred during this period. However, areas of vegetation clearing and regrowth were more visible between 2000 and 2007. The main source of confusion in the contingency matrix was due to heterogeneity within certain classes. It could also be due to spectral homogeneity among the classes. This research provides a baseline for future ecological landscape research and for the next management program in the area.

关键词： land change NDVI land cover protected areas Northern Togo

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Water quality in forest and village ponds in Burkina Faso(western Africa)

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Journal of Forestry Research 2017年第5期28卷 1039-1048页

作者： Bilass Zongo Frdric Zongo Aboubacar Toguyeni Joseph I.Boussim laboratoire de Biologie et Ecologie Vgtales Universit de Ouagadougou Unit de Recherche Aquaculture et biodiversit Aquatique laboratoire d'Etude et de Recherche sur les Ressources Naturelles et les Sciences Environnementales Universit Polytechnique de Bobo-Dioulasso

Forest ecosystems help conserve the quality of water resources in aquatic habitats. The conservation of biological diversity in aquatic and terrestrial ecosystems remains a communal concern. Aquatic ecosystems and resources are vulnerable but can be preserved and protected by forests. In sub-Saharan regions of Africa, water from ecosystems such as ponds still play important role in the livelihood of local populations. Water from temporary ponds is used by local populations for multiple needs; however, in this part of the world, the population is increasing, thus increasing human needs and activities and land use in the region. Land-use changes lead to deforestation, land degradation and the decline in freshwater, affecting human health and well-being. Forest degradation leads to the decline in ecosystem goods and services, particularly those related to watersheds. This study conducted in eastern Burkina Faso aimed to assess water quality of temporary ponds in protected forest areas (reserves) and surrounding villages. It was conducted in 61 temporary ponds where physical, chemical and biological variables were measured, such as water surface area, depth, transparency, macrophyte cover, pH, dissolved O2, conductivity, nutrient concentrations and algae biomass. The results showed that at p depth (p = 0.00), nutrient content (p = 0.00), and algae biomass (p = 0.04) were significantly higher outside reserves than inside reserves. In contrast, macrophyte cover (mean cover percentages 53 vs. 44.5%) and water transparency (p = 0.02) were higher inside reserves. The variations in conductivity and pH were not significant. All trends showed the influences of human activities on water characteristics and the role forests and land cover had in preventing negative human impacts and disturbance of temporary ponds. Forests and land cover are important to water quality conservation and algae biomass regulation in temporary ponds. Prot

关键词： Ecosystem services Pond water Reserves Variables Western Africa

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PHONONS IN POLYACENIC CHAINS

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Chinese Journal of Polymer Science 2006年第3期24卷 229-236页

作者： O.Rafil M.Tamine B.Bourahla R.Tigrine S.Amoudache A.Khater laboratoire de Physique et Chimie Quantique laboratoire de Physique de l'Etat Condensé

We have theoretically resolved phonon excitations in quasi-two-dimensional organic crystals of polyacenic semiconductor material which may be obtained by the pyrolytic treatment of phenol-formaldehyde resin. A model for studying the dynamical properties using three polyacene chains is proposed with the aim to present the vibrational properties of this structure. It employs the formalism of solid states in two dimensions which admit phonons. A simulation process of the two-dimensional lattice structure shows that elastic waves may explain the existence of vibrational modes in the frequency range 100-400 cm^-1. The presence of acoustic and optical like phonons is discussed in terms of the elastic force constants. A hyperfine resonance structure is obtained. It allows the analysis of the dynamical evolution in thin films of polyacene. It is found that the behavior of the phonon density of states exhibits resonance between modes in the structure.

关键词： Polymers Elastic waves Surface phonons Localized modes

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Effects of seed type and bruchid genotype on the performance and oviposition behavior of Zabrotes subfasciatus （Coleoptera： Bruchidae）

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Insect Science 2006年第4期13卷 309-318页

作者： ERICK D. M. CAMPAN BETTY BENREY Labomtory of Evolutionary Entomology Institute of Zoology University of Neuchatel Neuchatel Switzerland laboratoire Dynamique de la biodiversité Université Paul Sabatier Toulouse France

The effect of different bean varieties on the performance of the bruchid beetle Zabrotes subfasciatus Boheman （Coleoptera： Bruchidae）, was determined by using wild and cultivated seeds of the genus Phaseolus. Results showed that the quality of the host plant affected the performance and the oviposition behavior of female beetles. Overall, bruchid performance was higher on cultivated seeds than on wild seeds. It was also found that the oviposition behavior and the performance of their offspring differed between females that originated from wild versus cultivated seeds. We also demonstrated the importance of a genetic component in bruchid performance： longevity, fecundity, larval development, adult size, and the sex ratio of the progeny varied according to their matemal lineage （‘family＇）. For example, on the same host type, some females laid twice as many eggs as females from other‘families＇, and the sex ratio among the offspring correlated with that of their mother. Thus, the performance and behavior of Z. subfasciatus are not only affected by environmental factors such as the quality of the seeds on which they develop, but also have a genetic basis which can counterbalance a less suitable quality of the host plant. For a crop pest such as Z. subfasciatus, its ability to survive and adapt on host plants of differing quality may be an important attribute to consider for pest management.

关键词： bean beetles domestication host plant quality larval performance oviposition behavior

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Rotating instability in the vaneless diffuser of a radial flow pump

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Journal of Thermal Science 2008年第4期17卷 368-374页

作者： A.Dazin O.Coutier-delgosha P.Dupont S.Coudert G.Caignaert G.Bois laboratoire de Mécanique de Lille(UMR CNRS 8107) Arts et Métiers ParisTech laboratoire de Mécanique de Lille Ecole Centrale de Lille laboratoire de Mécanique de Lille CNRS

The paper refers to the behavior of a vaneless diffuser of a radial flow pump in partial flow operating conditions. Some experimental data have been obtained using 2D/2C PIV and unsteady pressure measurements within the diffuser, in various operating conditions. The experimental results at the lower flow rate are compared with two-dimensional numerical calculations.

关键词： Vaneless diffuser Radial flow pump Instability Particle Image Velocimetry Pressure measurements 2D calculations.

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Long Term Evaluation of Green Vegetation Cover Dynamic in the Atacora Mountain Chain(Togo) and its Relation to Carbon Sequestration in West Africa

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Journal of Mountain Science 2015年第4期12卷 921-934页

作者： Fousseni FOLEGA Yao Agbélessessi WOEGAN Dourma MARRA Kperkouma WALA Komlan BATAWILA Jean Leonardo SEBURANGA ZHANG Chun-yu PENG Dao-li ZHAO Xiu-hai Koffi AKPAGANA Université de Lomé Laboratoire de botanique et écologie végétale Faculté des Sciences The Key Laboratory for Forest Resources & Ecosystem Processes of Beijing Beijing Forestry University department of Biology Faculty of Science National University of Rwanda

The research was done in the Atacora Mountain chain in Togo which tended to assess the change of vegetation cover during a 24-year *** also aims to evaluate the dynamic of the net primary productivity(NPP) of the living plants over the same *** Landsat imagery covering three different periods(1987, 2000, and 2011) was pre-processed to correct atmospheric and radiometric parameters as well as gapfilling the 2011 SCL-off ***, the vegetation indices such as NDVI(normalized difference vegetation index), SR(simple ratiovegetation index), SAVI(soil-adjusted vegetation index), and CASA(carnegie- ames- stanford approach)model for NPP were applied on these images after masking the study *** results showed a quiet decrease in the vegetation *** vegetation loss was more significant from 2000 to 2011 than from1987 to 2000, and anthropogenic activities can be deemed as the main cause of the vegetation *** biomass assessment by NPP computation also showed a decrease over the *** to the change of the vegetation cover, the ecosystem net productivity was very low in 2011 compared to 2000 and *** seems that the general health condition of thevegetation, including its potentiality in carbon sinking,was negatively affected in this area, which has already been under threatened.A perpetual monitoring of these ecosystems by means of efficient techniques could enhance the sustainable management tools of in the framework of reducing emissions from deforestation and forest degradation(REDD).

关键词： Vegetation cover NPP Carbon sinking Biomass Togo

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X Y Z particles at BABAR

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Chinese Physics C 2010年第6期34卷 644-649页

作者： E.Prencipe LAPP-laboratoire de Annecy de Physique de Particules

This paper intends to shortly summarize the recent results on Spectroscopy, published from the BABAR Collaboration. The BABAR experiment is a B-factory, at SLAC, where asymmetric energy beams of electron-positron are accelerated and collide at the energy in the center of mass of T（4S）. In 9 years of data taking, BABAR had collected 433 fb^-1 equivalent luminosity on-peak-data at the T（4S） energy, 30 fb^-1 data at the T（3S） energy, 15 fb^-1 data at the T（2S） energy, and a scan around T（4S） was done, collecting 25 pb^-1 every 5 MeV. Thanks to the high luminosity achieved, it is possible to perform high precision measurements, and spectroscopy studies. An update on the measurement of the state X（3872） will be given, as final result published by using the whole dataset available. Then, a new preliminary Y（4260） measurement is reported, and the study of the invariant mass J/ψπ^＋π^- in ISR events is shown, where no evidence of the state Y（4050） is highlighted. As conclusion, the results on the angular distribution analysis performed on the state Z（4430） are reported.

关键词： spectroscopy charmonium BABAR

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Assessment of ship manoeuvrability by using a coupling between a nonlinear transient manoeuvring model and mathematical programming techniques

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Journal of Hydrodynamics 2013年第5期25卷 788-804页

作者： TRAN KHANH Toan OUAHSINE Abdellatif NACEUR Hakim EL WASSIFI Karima laboratoire Roberval Université de Technologie de Compiègne laboratoire LAMIH Université de Valenciennes Université Cadi Ayyad Faculté des Sciences et Techniques

In this paper, a numerical method based on a coupling between a mathematical model of nonlinear transient ship manoeuvring motion in the horizontal plane and Mathematical Programming （MP） techniques is proposed. The aim of the proposed procedure is an efficient estimation of optimal ship hydrodynamic parameters in a dynamic model at the early design stage. The proposed procedure has been validated through turning circle and zigzag manoeuvres based on experimental data of sea trials of the 190 000- dwt oil tanker. Comparisons between experimental and computed data show a good agreement of overall tendency in manoeuvring traiectories.

关键词： ship manoeuvrability hydrodynamics coefficients nonlinear transient dynamics sensitivity analysis mathematical pro- gramming

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In vitro antiplasmodial activity of crude extracts from Togolese medicinal plants

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Asian Pacific Journal of Tropical Medicine 2011年第2期4卷 129-132页

作者： Koffi Koudouvo Simplice D.Karou denise P.Ilboudo Kouami Kokou Kodjo Essien Kodjo Aklikokou Comlan de Souza Jacques Simpore Mensavi Gbeassor Centre de Recherche et de Formation sur les Plantes Medicinales(CERFOPLAM) Universite de LomeTogo laboratoire de botanique et d'Ecologie Vegetale Faculte des SciencesUniversite de LomeTogo Centre de recherche Biomoleculaire Pietro Annigoni(CERBA) OuagadougouBurkina Faso

Objective:To investigate the antimalarial effect of a few plants in Togo folk medicine. Methods:After ethnobotanical survey,Opilia celtidifolia,Pavetta corymbosa（***） and Tamarindus indica（***） were selected for *** vitro antimalarial tests were performed on crude extracts against fresh clinical isolates of Plasmodium falciparum using the semi ***:Different IC50,values of the extracts ranged from 2.042 to 100.000μg/mL. According to the results,the methanol extract of aerial part of *** followed by aqueous extract of fruit of *** were the most active(IC50 of 2.042 and 4.786μg/mL,respectively). Qualitative test revealed the presence of alkaloids in the leaves of *** that may be responsible for the activity of the ***:Our study provides scientific evidence for usage of plant in the folk medicine,and further studies are needed for identification and purification of the active principles.

关键词： Medicinal plants In vitro Screening Plasmodium falciparum

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Direct oxidation of methane to oxygenates over heteropolyanions

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Journal of Natural Gas Chemistry 2008年第3期17卷 309-312页

作者： Ouarda Benlounes Sadia Mansouri Chérifa Rabia Smain Hocine laboratoire de Chimie Appliqueé et de Génie Chimique Université Mouloud Mammeri laboratoire de Chimie du Gaz Naturel Institut de Chimie USTHB

Partial oxidation of methane to formaldehyde and methanol was studied at atmospheric pressure in the temperature range of 700-750 °C using heteropolycompound catalysts （NH4）6HSiMo11FeO40, （NH4）4PMo11FeO39, and H4PMo11VO40, which were prepared and characterized by various analysis techniques such as infrared, visible UV, XRD and DTA. O2 or N2O was used as the oxidizing agent, and the principal products of the reaction were CH3OH, CH2O, CO, CO2, and water. The conversion and the selectivity of products depend strongly on the reaction temperature, the nature of oxidizing agent, and the composition of catalyst.

关键词： methane oxidation heteropolycompounds methanol oxygenates

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