检索结果-南通市图书馆

Statistical Properties of The Exponentiated Nakagami Distribution

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Mathematics and System Science 2014年第3期4卷 180-185页

作者： Adepoju K.A chukwu a.u and Shittu, O.I Department of Statistics University of lbadan Nigeria.

This paper is an improvement over beta-Nakagami distribution developed by Shittu and Adepoju （2013）. Here we propose the addition of one parameter to the two parameter continuous Nakagami-m distribution （Nakagami, 1960） that was designed for modeling the fading of radio signals. The resulting distribution referred to as Exponentiated Nakagami （ENAK） distribution is a generalization of the classical Nakagami distribution. The statistical properties of the proposed distribution such as moments, moment generating function, the asymptotic behavior among others were investigated. The method of maximum likelihood is used to estimate the model parameters and the observed information matrix is derived. A real data set is used to compare the new model with the class of Nakagami distributions. Our findings showed that the Exponentiated Nakagami distribution is more flexible than beta-Nakagami distribution with better representation and less computational effort.

关键词： Nakagami exponentiated Nakagami Beta-Nakagami moments moment generating function

Geochemistry and petrogenetic evolution of metasedimentary rocks in Bunu Area,part of Kabba-Lokoja-Igarra schist belt,SW Nigeria

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Geochimica 2022年第5期41卷 765-788页

作者： M.S.Kolawole E.C.chukwu A.N.Agibe Department of Geology Federal UniversityOye-EkitiEkiti StateNigeria

Field and geochemical studies of the Bunu area,SW Nigeria,were carried out on gneiss-metasedimentary rocks that consist of migmatised gneiss,quartz-mica schist,and foliated and massive *** gneissmetasedimentary rocks are interbedded with meta-igneous rock(amphibolite),all of which are intruded by granitoid and cut by basic and felsic *** data on major,trace,and rare Earth elements of these rocks from the area were used to speculate on the petrogenetic and geodynamic evolution of the rocks in the ***,the metasedimentary rocks in the area have a restricted range of major oxides such as SiO_(2)and Al_(2)O_(3)with low average va.ues of FeO,MnO,CaO,and *** of average va.ues of HSFE such as Zr,Nb,and Y are moderately high in migmatitic gneiss,quartzmica schist,and low in both massive and foliated quartzite.ΣLREE average va.ues are 124.25,132.41,and18.64 ppm respectively for migmatite gneiss,quartz-mica schist,and low in both massive and foliated *** rocks are also generally enriched in Ba,Cs,Pb,u,Cr,Rb,and Zr and depleted in Be,Sr,Ti,Mo,Th,and *** enrichment–depletion in major oxides and trace elements of the rocks in this area is probably a consequence of the movement of metamorphic remobilized fluids within the rocks in the area during the Pan-African or earlier events as noted in the adjacent Egbe-Isanlu Schist belt.A further geochemical characterisation of the rocks in the area.using Log(Na_(2)O/KO)vs Log(SiO_(2)/Al_(2)O_(3)indicates that while the protolith of migmatised gneiss and quartzmica schist are greywackes to litharenite in compositions that of quartzites are sublitharenite to quartz *** the ternary plot of Al_(2)O_(3)-(CaO+Na_(2)O)-KO for metasedimentary rocks in the area,most migmatitic gneiss and quartz-mica schist rocks plot close to average shale while quartzites mostly tend to illite compositions and almost toward the Al_(2)O_(3)-apex of the diagram attesting to depletion of

关键词： Geochemical studies Metasedimentary rocks Geodynamic activities Protolith Passive continental margins

Inter-relationship of Various Results in Analysis of （14.0 MeV／u） Pb＋Pb Reaction using Mica and CN-85 Track Detectors

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2005年第1期22卷 69-71页

作者： F.N.Khattak E.u.Khan TabassumNasir J.J.Ba.uch F.u.Khan u.W.C. GomalUniversityDeraIsmailKhanPakistan RadiationPhysicsDivision PINSTECHNiloreIslamabadPakistan DepartmentofPhysics GomalUniversityDeraIsmailKhanPakistan

Two detector materials mica and cellulose-nitrate(CN)-85 have been used to study (14.0MeV/u) Pb + Pb reaction. Events of different multiplicities were registered in mica and CN-85 detectors using the 2π-geometry technique of solid state nuclear track detection. After removing the target material from the detectors the damaged trails in the detectors were revealed as tracks by proper chemical etching. The irradiated area of each sample was scanned and events of different multiplicities were traced. The binary events were bifurcated into elastic and inelastic events. The elastic binary events and three prong events, observed in the reaction, have been used to search out coefficients Cμν in the presence of both the detectors, for the reaction under study. using these coefficients 3- and 4-prong events have been analysed. From the detailed analysis of the results of (14.0MeV/u) Pb+Pb reaction, obtained from mica and CN-85 track detectors we observed a great resemblance of results obtained from the two detectors. Combining the results of both the detectors, we report some important outcomes.

关键词： CN-85轨迹探测器高能物理学铅原子碰撞反应固态

Observation　of　clouds　and　solar　radiation　over　the　Pacific　Ocean　as　relation　to　global　climate

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 1995年第2期14卷 201-207页

作者： Farn Pa.ungo Clarence Nagamoto Cecilia M. I. R. Girz Jeff Torgerson and Zhou Mingyu (Science and Technology Corporation, Boulder, CO, u. S. A.Air Resources Laboratory, NOAA, Boulder, CO, u. S. A.Forecast Systems Laboratory, NOAA, Boulder, CO, u. S. a.u

During a research cruise over the Pacific Ocean in 1989, solar irradiance was mea.ured with a broad-band pyranometer along the cruise track. Cloud cover was photographed with an all-sky time-lapse came ra. Cloud types were observed and recorded. The data show that both the types and the amounts of clouds affect radiation fluxes on the sea surface. For low-level and middle-level clouds, the correlations (r) between mea.ured irradiance (in Percent of calculated maximum irradiance) and cloud amount (in fraction of sky) were significant: r=-0. 79 and - 0. 66, respectively. For high-level clouds, the correlation was not significant: r=-0. 21. The results indicate that cloud shortwave forcing is a major modifier of the earth's surface insolation and change of cloud amount may affect global climate.

关键词： Solar irradiance cloud type cloud cover earth's surface insolation global climate

Nanoparticle type effects on flexural, interfacial and vibration properties of GFRE composites

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2016年第2期29卷 520-533页

作者： u.A.Khashaba Mechanical Engineering Department Faculty of Engineering King Abdulaziz University

Damping improvement in composite structures via introducing nanofillers generally has remarkable negative effects on the other mechanical properties. Therefore, in the present work, SiC and A1203 nanoparticles＇ infusion effects on the flexural, interracial and vibration properties of epoxy matrix and glass fiber reinforced epoxy （GFR/E） laminates were investigated. unidirectional （uD-GFR/E） and quasi-isotropic （QI-GFR/E） laminates with [0/± 45/90]s and [90/±45/0]s stack- ing sequences were hybridized by the optimum nanoparticles percentages. Results from off-axis flexural strengths of uD-GFR/E demonstrate good fiber/nanophased-matrix interracial bonding. The interlaminar shear stress between the adjacent layers with different orientations/strains of duc- tile QI-GFR/SiC/E laminates results in decreasing the flexural strengths respectively by 24.3% and 9.1% for [0/±45/90]s and [90/± 45/0]s stacking sequences and increasing the dissipated interfacial friction energy and thus the damping by 105.7% and 26.1%. The damping of QI-GFR/E, QI-GFR/SiC/E and QI-GFR/AI203/E laminates with [90/± 45/0]s stacking sequence was increased by 111.4%, 29.7% and 32.9% respectively compared to [0/± 45/90]s stacking sequence.

关键词： Flexural properties GFRE composites Interracial bonding Nanoparticles Non-destructive vibrationtechnique

General investigation for longitudinal wave propagation under magnetic field effect via nonlocal elasticity

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2015年第10期36卷 1305-1318页

作者： u.GVEN Department of Mechanical Engineering Yildiz Technical University

In this paper, the propagation of longitudinal stress waves under a longitu- dinal magnetic field is addressed using a.unified nonlocal elasticity model with two scale coefficients. The analysis of wave motion is mainly based on the Love rod model. The effect of shear is also taken into account in the framework of Bishop＇s correction. This analysis shows that the classical theory is not sufficient for this subject. However, this unified nonlocal elasticity model solely used in the present study reflects in a manner fairly realistic for the effect of the longitudinal magnetic field on the longitudinal wave propagation.

关键词： Rayleigh-Bishop rod nonlocal elasticity magnetic field wave propagation

Physico-chemical characterization of a farmland affected by wastewater in relation to heavy metals

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang university-Science A(Applied Physics & Engineering) 2008年第3期9卷 366-372页

作者： Emma.uel u. ONWEREMa.u Department of Soil Science and Technology Federal university of Technology PMB 1526 Owerri Nigeria

This study investigated selected properties of soils affected by wastewater and its relationship with some heavy metals. A free survey technique involving target sampling was used in siting soil profile pits. Soil samples were collected based on horizon differentiation and analyzed using routine and special analytical techniques. Soil data were subjected to correlation analysis using SAS program. Results show that all heavy metals studied had va.ues above critical limits in the polluted soils using known standards and that these biotoxic metals decreased with soil depths. Highly significant (P=0.01 and 0.05) relationships were established between investigated heavy metals and some soil properties, especially soil pH and organic matter. Further studies involving more edaphic properties, biotoxic metals and their bioaccessibility in crops growing on wastewater soils will surely enhance knowledge and management of these highly anthropogenically influenced soils of the study site.

关键词： Bioavailability Characterization Heavy metals Soil pollution Wastewater

Semi-solid near-net shape rheocasting of heat treatable wrought a.uminum alloys

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2010年第9期20卷 1719-1724页

作者： u.A.C uRLE Materials Science and Ma.ufacturing Council for Scientific and Industrial Research

Flexibility of the CSIR-RCS, induction stirring with simultaneous air cooling process, in combination with high pressure die casting is successfully demonstrated by semi-solid rheocasting of plates performed on commercial 2024, 6082 and 7075 wrought a.uminum alloys. Tensile properties were mea.ured for the above mentioned rheocast wrought a.uminum alloys in the T6 condition. The results showed that tensile properties were close to or even in some cases exceeded the minimum specifications. The yield strength and elongation of rheocast 2024-T6 exceeded the minimum requirements of the wrought alloy in the T6 condition but the ultimate tensile strength achieved only 90% of the specification because the Mg content of the starting alloy was below the commercial alloy specification. The strengths of rheocast 6082-T6 exceeded all of the wrought alloy T6 strength targets but the elongation only managed 36% of the required minimum due to porosity, caused by incipient melting during solution heat treatment, and the presence of fine intermetallie needles in the eutectic. The yield strength of rheocast 7075 exceeded the required one and the ultimate tensile strength also managed 97% of the specification; while the elongation only reached 46% of the minimum requirement also due to incipient melting porosity caused during the solution heat treatment process.

关键词： high pressure die casting (HPDC) a.uminum alloys as-cast condition T6 treatment incipient melting

Photoproduction of multi-meson final states–recent results from the Crystal-Barrel/TAPS experiment at ELSA-

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2009年第12期33卷 1105-1112页

作者： u. Thoma HISKP Universitt Bonn Nussallee 14-16 53115 Bonn Germany

Multi-meson final states such as γp →pπ0π0 and γp →pπ0η have been investigated with the Crystal-Barrel/TAPS experiment at ELSA. Baryon cascades via △π and △η and also via higher mass baryon resonances are clearly observed. Based on this data and on data from other reactions a partial wave analysis has been performed from which partial decay widths of various N＊ and △＊ states into the different pπ0π0 and pπ0η decay channels have been determined, leading partly to unexpected results. In addition, polarisation observables have been investigated. The beam asymmetry X has been determined for both reactions and double polarisation data.using a longitudinally polarised target and a circularly or linearly polarised photon beam has been taken. Given the angular coverage of the Crystal-Baxrel/TAPS experiment this data covers almost the full angular range and phase space. This data will provide new and important information for the partial wave analyses and bring us one step closer towards a complete experiment.

关键词： baryon spectroscopy photoproduction multi-meson final states polarisation observables