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Mathematical modeling of the impact of temperature variations and immigration on malaria prevalence in Nigeria

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International Journal of Biomathematics 2021年第8期14卷 215-252页

作者： eunice e.Ukwajunor eno e.e.Akarawak Israel Olutunji Abiala Department of Mathematics University of LagosLagos StateNigeria

The study examines the population-level impact of temperature variability and immigration on malaria prevalence in Nigeria,using a novel deterministic *** model incorporates disease transmission by immigrants into the *** the absence of immigration,the model is shown to exhibit the phenomenon of backward *** disease-free equilibrium of the autonomous version of the model was found to be locally asymptotically stable in the absence of infective ***,the model exhibits an endemic equilibrium point when the immigration parameter is greater than *** endemic equilibrium point is seen to be globally asymptotically stable in the absence of disease-induced *** and sensitivity analysis of the model,using parameter values and ranges relevant to malaria transmission dynamics in Nigeria,shows that the top three parameters that drive malaria prevalence(with respect to R_(0))are the mosquito natural death rate(μM),mosquito biting rate(bM)and the transmission rates between humans and mosquitoes(βH,βM).Numerical simulations of the model show that in Nigeria,malaria burden increases with increasing mean monthly temperature in the range of 22–28℃.Thus,this study suggests that control strategies for malaria should be intensified during this *** is further shown that the proportion of infective immigrants has marginal effect on the transmission dynamics of the ***,the simulations suggest that a reduction in the fraction of infective immigrants,either exposed or infectious,would significantly reduce the malaria incidence in a population.

关键词： Malaria immigration basic reproduction number temperature variability stability

Uncertainty and Certainty Relations for Pauli Observables in Terms of R′enyi entropies of Order α ∈(0;1]

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Communications in Theoretical Physics 2014年第3期61卷 293-298页

作者： Alexey e.Rastegin Department of Theoretical Physics Irkutsk State University

We obtain uncertainty and certainty relations of state-independent form for the three Paufi observables with use of the Renyi entropies of order α∈ （0; 1]. It is shown that these entropic bounds are tight in the sense that they are always reached with certain pure states. A new result is the condition for equality in Renyi-entropy uncertainty relations for the Pauli observables. Upper entropic bounds in the pure-state case are also novel. Combining the presented bounds leads to a band, in which the rescaled average Renyi a-entropy ranges for a pure measured state. A width of this band is compared with the Tsallis formulation derived previously.

关键词： Pauli observables Renyi entropy quantum measurement uncertainty principle

Aspect of the specialty metals potentials of pegmatites in western Oban Massif,Se Nigeria:A preliminary geochemical approach

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Chinese Journal Of Geochemistry 2012年第4期31卷 355-361页

作者： Oden M.I. Igonor e.e. Department of Geology University of CalabarP.M.B.1115 CalabarNigeria Petra Prospectors Limited Nigeria

Minerals in general and rare-metals in particular are of invaluable importance in the development and industrialization of any *** is true as they could affect a nation's national income,employment ratio,Gross National Product,and its entire *** study area(western Oban Massif-Se Nigeria) was investigated for its specialty metals bearing potentials because of(1) its geology,which is similar to other specialty metals bearing areas of the world;(2) past works,which points to the area as a likely source of economic deposit of such metals;and(3) the soaring cost of these rare metals in the light of recent upsurge in global information/telecommunication *** from the study,show that only cesium(Cs) and beryllium(Be) show minute signs or indications of enrichment if properly *** these metals should be studied in details to ascertain their economic *** rocks are too deficient in the other rare-metals(lithium,zirconium,strontium,tantalite,niobium,tungsten,gallium,and chromium) to warrant further analysis.

关键词：特种金属尼日利亚地球化学方法电位伟晶岩稀有金属矿地块国民生产总值

Species diversity in restoration plantings: Important factors for increasing the diversity of threatened tree species in the restoration of the Araucaria forest ecosystem

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Plant Diversity 2019年第2期41卷 84-93页

作者： Taylor e.Shaw School of Biological Sciences University of East Anglia Norwich Research Park

The Araucaria forest ecosystem in southern Brazil is highly threatened: less than one percent of the original forest remains, and what is left is a fragmented agro-mosaic of mostly early-to-late secondary forest patches among high-yield agriculture and timber monocultures. Forest restoration initiatives in this region aim to restore degraded areas, however the limited number of species used in restoration projects represents a missed opportunity for species-rich plantings. High diversity plantings represent a larger number of functional groups and provide a targeted conservation strategy for the high number of threatened species within this ecosystem. This study interviewed nurseries(Ns) and restoration practitioners(RPs) in Parana and Santa Catarina states to identify what species are being cultivated and planted, and what factors are driving the species selection process. An average of 20 species were reportedly used in restoration plantings, most of which are common, widespread species. Baseline data confirms that Ns and RPs have disproportionately low occurrences of threatened species in their inventories and plantings, supporting findings from previous research. Questionnaire responses reveal that opportunities for seed acquisition are an extremely important factor in order for nurseries to increase their diversity of cultivated species. Results also suggest that facilitating speciesrich plantings for restoration practitioners would only be feasible if it did not increase the time required to complete planting projects, as it would minimize their ability to keep costs low. This study proposes solutions for increasing the number of species used in restoration practicedsuch as developing a comprehensive species list, fostering knowledge-sharing between actors, creating seed sharing programs, and increasing coordination of planting projects. Long-term strategies involve complimenting traditional ex situ approaches with emerging inter-situ and quasi in situ conserv

关键词： Restoration Araucaria forest Threatened species Nurseries Restoration practitioners Decision-making

Correlation of Fe^(2+) isomer shifts with bond lengths and bond strengths in neso- and sorosilicates

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Science China Chemistry 1995年第4期38卷 478-483页

作者：李哲 e.DeGrave Institute of Geology Chinese Academy of Sciences Beijing 100029 China Laboratory of Magnetism Gent State University Proeftuinstraat 86 B-9000 Gent Belgum

An evaluation of Mbssbauer isomer shift and quadrupole splitting data of Fe2+ in a number of structurally well characterized neso- and sorosilicates is presented. It is found that the nearly linear correlations exist both between the isomer shift and the bond length and between the isomer shift and the bond strength. These correlations are discussed on the basis of the variation of the s-electron density at the Fe2+ nuclei with the chemical bond characteristics.

关键词： Mossbauer effect isomer shift nesosilieates sorosilicates.

Impacts of climate change on the ecotoxicology of chemical contaminants in estuarine organisms

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Current Zoology 2015年第4期61卷 641-652页

作者： Marie e. DeLOReNZO NOAA National Ocean Service National Centers for Coastal Ocean Science Center for Coastal Environmental Health andBiomolecular Research 219 Fort Johnson Rd. Charleston SC 29412 USA

Global climate change effects will vary geographically, and effects on estuaries should be independently considered. This review of the impacts of climate change on the ecotoxicology of chemical contaminants aims to summarize responses that are specific to estuafine species. estuarine organisms are uniquely adapted to large fluctuations in temperature, salinity, oxygen, and pH, and yet future changes in climate may make them more susceptible to chemical contaminants. Recent research has hig- hlighted the interactive effects of chemical and nonchemical stressors on chemical uptake, metabolism, and organism survival. Assessments have revealed that the nature of the interaction between climate variables and chemical pollution will depend on es- tuarine species and life stage, duration and timing of exposure, prior stressor exposure, and contaminant class. A need for further research to elucidate mechanisms of toxicity under different abiotic conditions and to incorporate climate change factors into toxicity testing was identified. These efforts will improve environmental risk assessment of chemical contaminants and manage- ment capabilities under changing climate conditions [Current Zoology 61 （4）： 641-652, 2015].

关键词： Climate Toxicity Metals Pesticides Oil esmarine

Comparing the behavior of orbits in different 3D dynamical models for elliptical galaxies

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Research in Astronomy and Astrophysics 2012年第4期12卷 383-399页

作者： euaggelos e.Zotos Department of Physics Section of Astrophysics Astronomy and Mechanics Aristotle University of Thessaloniki 541 24 Thessaloniki Greece

We study the behavior of orbits in two different galactic dynamical models, describing the motion in the central parts of a triaxial elliptical galaxy with a dense nucleus. Numerical experiments show that both models display regular motion together with extended chaotic regions. A detailed investigation of the properties of motion is made for the 2D and 3D Hamiltonian systems, using a number of different dynamical parameters, such as the Poincare′ surface of a section, the maximal Lyapunov Characteristic exponent, the S（c） spectrum, the S（w） spectrum and the P （f ） indicator. The numerical calculations suggest that the properties of motion in both potentials are very similar. Our results show that one may use different kinds of gravitational potentials in order to describe the motion in triaxial galaxies while obtaining quantitatively similar results.

关键词： galaxies kinematics and dynamics-- galaxies elliptical

Nutritional and microbiological evaluations of chocolate-coated Chinese chestnut (Castanea mollissima) fruit for commercial use

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2008年第9期9卷 675-683页

作者： Mahamadou e. GOUNGA State Key Laboratory of Food Science & Technology School of Food Science & Technology Jiangnan University

In recent years, China has become an increasingly important and the largest chestnut producer in the world. This study aimed to evaluate the nutritional value and microbiological quality of the roasted freeze-dried Chinese chestnut (Castanea mollissima) (RFDC) coated with dark chocolate (DCC) and milk chocolate (MCC) for industrial use and commercial consumption. Chocolate coating significantly improved the nutritional value of chestnut. RFDC had high levels of starch (66.23%) and fibers (3.85%) while DCC and MCC contained significantly high amounts of sucrose, protein, fat and minerals. Furthermore, the protein content doubled in MCC rather than in DCC. This could be attributed to the different formulations in the two products. Milk powder and whey protein constituted the source of protein in MCC while cocoa powder added to MCC formulation constituted an additional source of minerals. The amino acid profile showed differences in amino acid composition related to the sample’s protein content, indicating their good nutritional quality. The moisture contents in all RFDC, DCC and MCC were suitable for industrial processing. These results provide information about the additional nutrients of chocolate-coated chestnut and confirm that the product is an interesting nutritional food. The combination of freeze-drying and chocolate-coating generally results in greater reductions on microbiological loads, extending shelf life of harvested chestnut for commercial application. This is an alternative strategy to add value to chestnut, minimizing the significant losses in harvested fruits and providing a wider range of choices of new products to the consumer disposal.

关键词： Chestnut Coating Dark chocolate Milk chocolate Nutritional qualities Microbiological analysis

MeASUReMeNT OF HYDRODYNAMIC FORCeS ACTING ON A CIRCULAR CYLINDeR NeAR A PLANe BOUNDARY IN STeADY FLOW

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Journal of Hydrodynamics 1992年第1期4卷 53-64页

作者： e, Xuequan Li, Zhanhua Inst of Mechanics Chinese Acad of Sciences Beijing China

Object of the present work is to study the characteristics of the hydrodynamic forces on the circular cylinder near the plane wall at various distance in a steady flow. experiments were conducted in the gravity-type water tunnel and maximum flow velocity was 1 m/sec. The hydrodynamic coefficients of the cylinder and the vortex shedding frequency were measured using a balance with water proof strain gauge in a water tunnel under the conditions of Reynolds number ranged from 4.54×103 to 1.76×105, gap-to-diameter ratio in Oe boundary layer thickness on the plane wall at the station of the centre of the model being smaller than 0.10 D. The change of these coefficients with Re and G/D was found. The lift frequency shows that a strong non-linear coupling action appears when G/D reaches 0.5 and the vortex shedding is supperessed when G/D is 0.2.

关键词： Flow of Fluids Cylinders