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Assessment of Vulnerability of Oxisols to Compaction in the Cerrado Region of Brazil

Pedosphere 2010年第2期20卷 252-260页

作者： A.E.AJAYI M.S.DIAS JUNIOR N.CURI A.OKUNOLA T.T.TEIXEIRA SOUZA B.SILVA PIRES Department of Agricultural Engineering Federal University of Technology Departamento de Ci encia do Solo Universidade Federal de Lavras Federal College of Agriculture Fundacao de Ensino Superior de Passos Universidade do Estado do Minas Gerais

The Cerrado region of Brazil,one of the fastest-growing agricultural areas in the world,is undergoing very rapid mechanization;this development is good for the country's economy but may also snowball into substantial loss of agricultural land and other environmental degradation if the soil susceptibility and vulnerability to compaction is not well *** this study we explored different techniques for estimating soil intrinsic abilities to withstand applied pressure using the prevalent Oxisols of the Cerrado region under native *** samples were collected from three sites within the region and subjected to 1) compressibility test;2) manual penetration resistance test;3) automated penetration resistance test;and 4) packing density *** four methods produced analogous *** results showed the significant influence of soil structure on the inherent strength and compaction susceptibility of the *** also established the association of soil structure with the mineralogy of the *** is noteworthy that the packing density which was developed from very simple and easily obtained parameters could give a picture of the tendency of the soil to ***,this approach would be useful in developing compaction susceptibility maps for the *** could be concluded that most of the Oxisols in the Cerrado region would support mechanized agricultural production very ***,there is need for careful management of the mechanization process to avert *** management techniques should include conservationist practices such as no till in order to maintain as much as possible the favorable structure and drainage of these very old soils.

关键词： compressibility packing density penetration resistance soil structure

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Influence of temperature on preparing mesoporous mixed phase N/TiO2 nanocomposite with enhanced solar light photocatalytic activity

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Frontiers of Materials Science 2019年第4期13卷 352-366页

作者： Elias ASSAYEHEGN Ananthakumar SOLAIAPPAN Yonas CHEBUDIE Esayas ALEMAYEHU Materials Science and Technology Division National Institute for Interdisciplinary Science and Technology(CSIR-NIIST)Thiruvananthapuram-695019India National Centre for Catalysis Research and Department of ChemistryIndian Institute of Technology(IIT)-MadrasChennai-600036India Faculty of Materials Science and Engineering Jimma UniversityP.O.Box 378JimmaEthiopia Department of Chemistry Addis Ababa UniversityP.O.Box 1176Addis AbabaEthiopia Faculty of Civil and Environmental Engineering Jimma UniversityJimmaP.O.Box 378Ethiopia

Nitrogen-doped titanium dioxide(N/TiO2)nanophotocatalysts were successfully synthesized in the presence of environmentally benign nitrogen dopant source,guanidinium chloride,by the sol-gel *** effect of calcination temperature(300–600℃)on their physicochemical properties was investigated by means XRD,XPS,FESEM,HRTEM,Raman spectroscopy,UV-vis DRS,PL and ***,their photocatalytic activities were evaluated against rhodamine B(RhB)degradation under direct sun *** showed that the crystal phase of spheroidal N/TiO2 nanoparticles was changed from anatase(300℃)to rutile(600℃)via an intermediate anatase/rutile(A/R)mixed phase(400–500℃),and the RhB photodegradation performance was increased with the decrease of the calcination ***,N/TiO2 prepared at 400℃demonstrated the best degradation performance(99%)after 5 h *** enhanced performance with high photostability was mainly attributed to its higher surface area and pore volume,stronger light absorption,and lower recombination *** nanomaterials have practical applications for environmental remediation.

关键词： nitrogen doping TiO2 rhodamine B mixed photocatalyst guanidinium chloride

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Effects of Dracaena arborea(Dracaenaceae) on sexual dysfunction in 4 weeks hyperglycemic male rats

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Asian Pacific Journal of Tropical Medicine 2014年第8期7卷 609-619页

作者： Wankeu-Nya M Watcho P Nguelefack TB Cairo-Juarez M Tapondjou L Kamanyi A Animal Physiology and Phytopharmacology Laboratory Department of Animal BiologyUnivcrsity of DschangP.O.BOX 67 Dschang-Cameroon Laboratory of Animal Biology and Physiology Department of Animal Organisms BiologyUniversity of DoualaP.O.BOX 24157Douala-Cameroon Laboratorio de Comportamiento Reproductive Escuela de Medicina Veterinaria y ZootecniaUniversidad Autnoma de Tlaxeala.TlaxealaC.P 90000Mexico Organic Chemistry Laboratory Department of chemistryUniversity of DschangP.O.BOX 67 Dschang-Cameroon

Objective:To investigate the effects of Dracaena arborea(***) on the sexual behavior parameters in experienced type-1 diabetic ***:Aqueous and ethanol(100 and 500mg/kg respectively)extracts of dried root barks of *** citrate(1.44 mg/kg),trimethylamine-N-oxide(TMAO,20 mg/kg)and distilled water(110 mL/*** orally administered to 4 weeks streptozolocin-induced diabetic *** latency and frequency(***),intromission latency and frequency(IL,IF) and post-ejaculatory interval(PEI) were measured by ejaculating series during 90 min once a week for 4 *** was determined at the beginning and at the end of the treatment Results:*** did not show any major antihvperglycemic *** to the control group,a significant(P<0.05-0.001)increase in MF and IF was noticed in rats treated with sildenafil citrate(89.71% and 90.07% respectively),aqueous(500 mg/kg.88.08%and 88.749;respectively) and ethanol(100 mg/kg;89.53%and 89.17respectively) extracts of *** after two weeks(series 1) of ***,IL and PEI were significantly(P<0.05-0.001) decreased after 4 weeks of daily treatment[sildenafil citrate(96.***.96.31%and 34.98%),and *** aqueous 500 mg/kg(94.***.94.33% and 66.609;i and ethanol extracts 100 mg/kg(96.***.97.089;and 64.26%)].Conclusions:These aphrodisiac potentials of *** in experienced diabetic rats could be due to the antioxidant and androgenic properties of phenols,*** and sterols revealed in the plant extracts.

关键词： Erectile dysfunction Streptozotocin Diabetes Dracaena arborea Aphrodisiac properties Rats

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Assessment of genetic variation in tomato (Solanum lycopersicum L.) inbred lines using SSR molecular markers

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Journal of Genetics and Genomics 2008年第6期35卷 373-379页

作者： Solomon Benor Mengyu Zhang Zhoufei Wang Hongsheng Zhang State Key Lab of Crop Genetics and Germplasm Enhancement College ofAgriculture Nanjing Agricultural University Nanjing 210095 China Department of Agrobiodiversity Institute of Crop Science University of Kassel 34109 Kassel Germany and Leibniz Institute of Plant Genetics and Crop Plant Research （IPK） Corrensstr. 3 06466 Gatersleben Germany

A study was conducted to determine the genetic diversity of 39 determinate and indeterminate tomato inbred lines collected from China, Japan, S. Korea, and USA. Using 35 SSR polymorphic markers, a total of 150 alleles were found with moderate levels of diversity, and a high number of unique alleles existing in these tomato lines. The mean number of alleles per locus was 4.3 and the average polymorphism information content （PIC） was 0.31. Unweighted Pair Group Method with Arithmetic Mean （UPGMA） clustering at genetic similarity value of 0.85 grouped the inbred lines into four groups, where one USA cultivar formed a separate and more distant cluster. The most similar inbred lines are from USA, both with determinate type, whereas the most different lines are from USA （Us-16） and Japan （Ja-2） with determinate and indeterminate growth habit, respectively. Clustering was consistent with the known information regarding geographical location and growth habit. The genetic distance information reported in this study might be used by breeders when planning future crosses among these inbred lines.

关键词： Solanum lycopersicum L SSR markers genetic diversity growth characterization

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Characterization and kinetic study on ammonia leaching of complex copper ore

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Transactions of Nonferrous Metals Society of China 2014年第5期24卷 1587-1595页

作者： A.A.BABA M.K.GHOSH S.R.PRADHAN D.S.RAO A.BARAL F.A.ADEKOLA Department of Industrial Chemistry University of Ilorin CSIR-Institute of Minerals and Materials Technology

Ammonia leaching kinetics of a complex Cu-ore assaying 8.8% Cu and 36.1% Fe was examined. Mineralogical characterization indicated that the major phase of the ore was siderite with chalcopyrite as the major sulfide mineral. The effects of parameters such as agitation, temperature, NH3 concentration, particle size and oxygen partial pressure （Po2） were investigated. Under the standard leaching conditions of 125-212 μm particle size, 120 ℃, 1.29 mol/L NH3 and 202 kPa ofpo2, about 83% Cu could be selectively extracted in 2.5 h. However, when using higher NH3 concentration and lower particle size, more than 95% extraction was achieved. The leaching process was found to be surface reaction controlling. The estimated activation energy was （37.6±1.9） kJ/mol and empirical orders of reaction with respect topos and [NH3] were about 0.2 and 1, respectively.

关键词： ammonia leaching chalcopyrite siderite leaching kinetics

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Leaf gas exchange characteristics,biomass partitioning,and water use efficiencies of two C4 African grasses under simulated drought

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Grassland Research 2023年第1期2卷 37-45页

作者： Kevin Z.Mganga Jana Kuhla Andrea Carminati Johanna Pausch Mutez A.Ahmed Copernicus Institute of Sustainable Development Utrecht UniversityUtrechtthe Netherlands Department of Agricultural sciences South Eastern Kenya UniversityKituiKenya Bayreuth Center of Ecology and Environmental Research(BayCEER) University of BayreuthBayreuthGermany Department of Environmental Systems Science ETH ZurichZürichSwitzerland Department of Land Air and Water ResourcesUniversity of California DavisDavisCaliforniaUSA

Background:Few studies have evaluated the effect of drought on the morphophysiological characteristics of African C_(4) *** investigated how drought affects leaf gas exchange characteristics,biomass partitioning,and water use efficiencies of Enteropogon macrostachyus and Cenchrus ***:The grasses were grown in a controlled environment under optimum conditions,that is,70%of the maximum water‐holding capacity(WHC)for the first 40 ***,half of the columns were maintained under optimum or drought conditions(30%of maximum WHC)for another 20 ***:Under optimum conditions,*** showed a significantly higher photosynthetic rate,stomatal conductance,and transpiration rate than *** decreased the photosynthetic rate,stomatal conductance and transpiration rate only in *** net photosynthetic rate,stomatal conductance,and leaf transpiration of *** did not differ significantly under optimum and drought *** showed an increase in its water use efficiencies under drought to a greater extent than ***:Our results demonstrate that *** is more sensitive to drought than *** decrease in the intercellular CO_(2) concentration and the increase in stomatal limitation with drought in *** and *** suggest that stomatal limitation plays the dominant role in photosynthesis of the studied African C_(4) grasses.

关键词： biomass fractions C_(4)grasses drought photosynthesis stomatal conductance transpiration

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Land use patterns and tree species diversity in the Volta Geological Unit, Togo

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Journal of Mountain Science 2019年第8期16卷 1869-1882页

作者： FOLEGA Fousseni ATAKPAMA Wouyo WALA Kperkouma MUKETE Beckline SHOZO Shibata AKIRA Osawa ZHAO Xiu-hai AKPAGANA Koffi Geomatic and Ecosystems Modeling/Laboratory of botany and Plant Ecology Faculty of SciencesUniversity of LomeLome01BP1515Togo Key Laboratory for Forest Resources&Ecosystem Processes Beijing Forestry UniversityBeijing 100083China Graduate School of Global Environmental Studies Kyoto UniversityKyoto 606-8501Japan Department of Forest Management Beijing Forestry UniversityBeijing 100083China

The application of remote sensing in understanding tree species structural diversity and land use patterns relationship is imperative for reforestation and biodiversity conservation efforts. This study assesses land use patterns and tree species structural diversity in previously reforested hilly sandstone regions of northern Togo. The physical height, and diameter at breast height(DBH) more than 5 cm of all tree species in each given plot were measured in summer 2017. A total of 75 plots of 900 m^2 installed along the toposequence were recorded. In addition, a semi-supervised classification of Landsat 8 images in January of 2018, was also used to classify the land use patterns. 36 tree species and 19 families were recorded for the entire study area. Meanwhile, 19 tree species and 15 families were recorded for the previously afforested zones. The most abundant species included the Sterculiaceae, Zygophyllaceae, Meliaceae, and Mimosaceae. The trees stand structure represented 8.61 ± 0.57 m, 11.28 ± 1.76 cm, and 0.018 ± 0.009 m^2 per hectare for height, diameter and basal area respectively. Major land use patterns were tree and shrub savannahs, parklands and croplands which represented over 60% of the landscape. It is necessary to examine the regeneration and vegetative multiplication potentials of the most frequent and abundant tree species for any eventual future afforestation programs in these hilly sandstone regions of northern Togo.

关键词： Ecological diversity Land use Ecological restoration Forest degradation Togo

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Bioleaching of Zn(Ⅱ) and Pb(Ⅱ) from Nigerian sphalerite and galena ores by mixed culture of acidophilic bacteria

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Transactions of Nonferrous Metals Society of China 2011年第11期21卷 2535-2541页

作者： Alafara A.BABA Folahan A.ADEKOLA Rasaq F.ATATA Risikat N.AHMED Sandeep PANDA Department of Chemistry University of Ilorin Department of Biological sciences Fountain University Department of Microbiology University of Ilorin Bioresources Engineering Department Institute of Minerals and Materials Technology

Zn（Ⅱ） and Pb（Ⅱ） from Nigerian sphalerite and galena ores were bioleached by a mixed culture of acidophilic *** influences of pH and ferric ion on the bioleaching rates of sphalerite and galena were *** result shows that pH 2.1 and 2.7 are favourable for the leaching of Zn（Ⅱ） and Pb（Ⅱ） from sphalerite and galena,*** was observed that the use of agarose-simulated media caused cells to excrete exopolymers containing ferric ions which enhanced *** oxidation equilibrium for sphalerite and galena took 3 and 4 d,*** 38.3% sphalerite and 34.2% galena were leached within 1 d and approximately 92.0% Zn（Ⅱ） and 89.0% Pb（Ⅱ） were recovered in 5 d,*** unleached residual products were examined by X-ray diffraction for sphalerite,revealing the presence of elemental sulphur（S）,zinc sulphate（ZnSO4） and few traces of calcium aluminate（Ca3Al2O6）.The XRD pattern also indicates the presence of elemental sulphur（S）,lead sulphate（PbSO4） and few traces of itoite [Pb（S,Ge）（O,OH）4] and cobalt lead silicate [Pb8Co（Si2O7）3] in the unleached galena ore.

关键词： sphalerite galena zinc(Ⅱ) lead(Ⅱ) oxidation acidophilic bacteria

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Hydroclimatological changes in the Bagmati River Basin, Nepal

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Journal of Geographical sciences 2013年第4期23卷 612-626页

作者： Yam Prasad DHITAL 汤秋鸿施建成 Department of Environmental Science and Engineering School of Science Kathmandu University Nepal Institute of Geographic sciences and Natural Resources Research CAS Beijing 100101 China Institute of Remote Sensing Applications CASinstitute of Remote Sensing Applications CAS Beijing 100101 China

Study on hydroclimatological changes in the mountainous river basins has attracted great interest in recent years. Changes in temperature, precipitation and river discharge pattern could be considered as indicators of hydroclimatological changes of the river basins. In this study, the temperatures （maximum and minimum）, precipitation, and discharge data from 1980 to 2009 were used to detect the hydroclimatological changes in the Bagmati River Basin, Nepal. Simple linear regression and Mann-Kendall test statistic were used to examine the significant trend of temperature, precipitation, and discharge. Increasing trend of temperature was found in all seasons, although the change rate was different in different seasons for both minimum and maximum temperatures. However, stronger warming trend was found in maximum temperature in comparison to the minimum in the whole basin. Both precipitation and discharge trend were increasing in the pre-monsoon season, but decreasing in the post-monsoon season. The significant trend of precipitation could not be observed in winter, although discharge trend was decreasing. Furthermore, the intensity of peak discharge was increasing, though there was not an obvious change in the intensity of maximum precipitation events. It is expected that all these changes have effects on agriculture, hydropower plant, and natural biodiversity in the mountainous river basin of Nepal.

关键词： Bagmati River Basin hydroclimatological change temperature precipitation discharge

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Polymer Sensitized Quasi Solid-State Photovoltaic Cells Using Derivatives of Polythiophene

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Journal of Materials Science & Technology 2006年第6期22卷 811-816页

作者： G.K.R.Senadeera J.M.R.C.Fernando Institute of Fundamental Studies Hantane RoadKandySri Lanka Institute of Fundamental Studies Hantane RoadKandySri Lanka Postgraduate Institute of ScienceUniversity of PeradeniyaPeradeniyaSri Lanka

Substituted thiophene sensitized, nanocrystalline TiO2-based quasi solid-state solar cells were fabricated by using either poly （3-thiophene acetic acid）（P3TAA） or a copolymer with poly （3-thiophene acetic acid）-poly （hexyl thiophene）（P3TAA-PHT） polymers and copper iodide （Cul） as a hole conducting material together with an ionic liquid 1-ethyl-3-methylimidazolium bis （trifluoromethylsulfonyl） amide and lithium bis （triflu- oromethanesulfone） imide as additives for charge transport promotion. Dramatic enhancements in the cell performances were observed with the additives in Cul. While the cell sensitized with P3TAA generated a short-circuit photocurrent of -1.45 ***^-2, an open-circuit photovoltage of -345 mV with a total power conversion efficiency of -0.3% under simulated full sunlight of 100 mW-cm^-2 （air mass： 1.5）, the cell sensitized with copolymer P3TAA-PHT delivered -0.25% efficiency under the same conditions with -1.23 mA-cm^-2 as photocurrent and -371 mV as photovoltage.

关键词： Solar cells Polymers Titanium dioxide

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