检索结果-南通市图书馆

Role of ore mineralogy in optimizing conditions for bioleaching low-grade complex sulphide ores

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2008年第5期18卷 1234-1246页

作者： P.A.OLUBAMBI s.NDLOVU j.H.POTGIETER j.O.BORODE school of Chemical and Metallurgical Engineering University of the Witwatersrand Department of Metallurgical and Materials Engineering Federal University of Technology

The role that ore mineralogy plays in understanding and optimizing the conditions favouring the bioleaching of complex sulphide ore containing high amounts of siderite was studied using mixed cultures of mesophilic bacteria,with emphasis on zinc,lead and copper *** influencing parameters investigated include particle size,stirring speed,volume of inoculum,pulp density,and *** results show that the mixed mesophilic cultures can extract about two and a half times the amount of zinc than copper over an equivalent period of *** highest zinc and copper recoveries of 89.2% and 36.4% respectively are obtained at particle size of 75 μm,stirring speed of 150 r/min,pulp density of 10% (w/v),12% (v/v) inoculum concentration,and a pH of *** in elemental composition within different particle sizes resulting from the mineralogy of the ore account for the bioleaching behaviour at varying particle *** dissolution at varying pulp density,volume of inoculum,solution pH and the low solution potential observed are also influenced by ore mineralogy.

关键词：硫化物矿石矿石矿物学生物浸取加工参数

A mild, configurable, flexible CoNi-LDH（v）/Zn battery based on H-vacancy-induced reversible Zn2+ intercalation

在线全文

学校读者我要写书评

暂无评论

journal of Energy Chemistry 2025年第1期100卷 498-508页

作者： Xinyue Cheng Dingsheng Wu Hao Gao Qingqing Wang Pengfei Lv sam s.Yoon Qufu Wei Key Laboratory of Eco-textiles Ministry of Education Jiangnan University school of Mechanical Engineering Korea University

Flexible Zn-based batteries have attracted increasing research interest as essential components of wearable energy storage ***,the advancement of flexible aqueous Zn-based batteries based on Co-Ni layered double hydroxide （CoNi-LDH） as the cathode material is hampered by their poor cycling stability and the corrosiveness of alkaline ***,CoNi-LDH nanosheets enriched with H vacancies (CoNi-LDH（v）) were constructed on a flexible carbon cloth （CC） substrate via electrochemical deposition and *** Zn-based battery comprising CoNi-LDH（v）@CC as the cathode exhibited highly reversible conversion reactions and stable operation in 3 M ZnsO4electrolyte （pH=4）.The battery delivered an excellent specific capacity (225 mA h g-1,0.26 mA h cm-2),acceptable cycling stability（53.9%,900 cycles）,and high discharging *** abundant H vacancies served as active sites for the reversible intercalation of Zn2+and the extravasation of NO3-generated channels and space for Zn2+transport and storage,together enabling an excellent Zn2+storage ***,a sandwich-structured solid-state CoNi-LDH（v）@CC//Zn@CC battery was fabricated and was found to exhibit a noteworthy electrochemical performance and mechanical *** a proof of concept,the unencapsulated battery powered a digital watch under various deformation conditions and operated stably for 80 ***,the flexible battery displayed outstanding customizability,maintaining an open-circuit voltage of 1.42 V even after being cut *** proposed engineering strategy contributes to the realization of textiles with truly wearable energy-storage devices.

关键词： CoNi/Zn battery H vacancies Mild aqueous electrolyte Tailorable battery Wearable energy storage device

Numerical computations of magnetohydrodynamic mixed convective flow of Casson nanofluid in an open-ended cavity formed by earthquake-induced faults

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第12期45卷 2215-2230页

作者： M.IBTEsAM s.NADEEM j.ALZABUT Department of Mathematics Quaid-i-Azam UniversityIslamabad 44000Pakistan Department of Mathematics and sciences Prince Sultan UniversityRiyadh 11586Saudi Arabia Department of Mathematics Wenzhou UniversityWenzhou 325035Zhejiang ProvinceChina Department of Industrial Engineering OSTIM Technical UniversityAnkara 06374Turkiye

The numerical computations for the magnetohydrodynamic(MHD) mixed convective flow of a non-Newtonian Casson nanofluid(Cu/H2O) within an open-ended cavity formed by earthquake-induced faults are analyzed, aiming to investigate the fluid dynamics and convection processes of geothermal systems. such cavities, typically found in energy reservoirs, are primarily caused by tensional fault zones formed due to the accumulated energy from the disintegration of radioactive materials. These cavities play a crucial role in energy transmission, particularly in the form of heat. The focus of this paper is on the laminar, steady, and incompressible fluid flow. An inclined magnetic field is applied with an angle of inclination z = 30°. Additionally, a heated material with two vertical corrugated walls is placed at the center of the cavity. The governing nonlinear partial differential equations(PDEs) are transformed into the equations with a nondimensional form. The Galerkin finite element method(FEM) is implemented to solve the dimensionless equations. The impacts of key variables, including the Reynolds number Re, the volume fraction(0.01≤ φ_(p)≤0.05), the Hartmann number Ha, and the Casson parameter(0.5≤γ≤1.0), on the velocity and temperature distributions are studied. The analysis of the fluid flow and the heat transfer rate is conducted. The results indicate that the velocity increases as the volume fraction and the Reynolds number ***, the heat transfer rate rises with the Reynolds number and the volume fraction,while decreases with the higher Hartmann number. The Nusselt number increases with the volume fraction and the Reynolds number but decreases with the Hartmann number.

关键词： nanofluid magnetohydrodynamic(MHD) Casson fluid mixed convection finite element method(FEM)

Generation of linear and nonlinear waves in numerical wave tank using clustering technique-volume of fluid method

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2012年第9期33卷 1179-1190页

作者： H.sAGHI M.j.KETABDARI s.BOOsHI Department of Civil Engineering Ferdowsi UniversityMashhad 91779-4897Iran Faculty of Marine Technology Amirkabir University of TechnologyTehran 15875-4413Iran

A two-dimensional （2D） numerical model is developed for the wave sim- ulation and propagation in a wave flume. The fluid flow is assumed to be viscous and incompressible, and the Navier-stokes and continuity equations are used as the governing equations. The standard k-e model is used to model the turbulent flow. The Navier- stokes equations are discretized using the staggered grid finite difference method and solved by the simplified marker and cell （sMAC） method. Waves are generated and propagated using a piston type wave maker. An open boundary condition is used at the end of the numerical flume. some standard tests, such as the lid-driven cavity, the constant unidirectional velocity field, the shearing flow, and the dam-break on the dry bed, are performed to valid the model. To demonstrate the capability and accuracy of the present method, the results of generated waves are compared with available wave theories. Finally, the clustering technique （CT） is used for the mesh generation, and the best condition is suggested.

关键词： numerical wave tank free surface simulation Navier-stokes equation stag-gered grid clustering technique (CT) wave generation

Cross-focusing of two chirped Gaussian laser beams and THz wave generation in plasmas of multi-ion species under a weakly relativistic and ponderomotive regime

在线全文

学校读者我要写书评

暂无评论

Plasma science and Technology 2022年第10期24卷 1-11页

作者： M R jAFARI MILANI s REZAEI M j jAFARI Photonics and Quantum Technologies Research school Nuclear Science and Technology Research InstituteTehran 14665-678Iran Plasma and Fusion Research school Nuclear Science and Technology Research InstituteTehran 14399-51113Iran

The generation of terahertz(THz)waves via the beating of two high-intensity chirped Gaussian lasers in a multi-ion-species plasma is numerically studied by taking into account the weak relativistic and ponderomotive regime of *** coupled differential equations for beamwidth parameters are extracted by introducing the dielectric function of such plasma and using WKB and paraxial ray *** amplitude of THz radiation at beat frequency resulting from the nonlinear current density induced by the beat ponderomotive force of the cross-focusing of beams was *** impacts of the chirp frequency parameter,initial laser intensity and initial ionic species density(specifically,the presence of singly and doubly charged ions)in the plasma on THz generation were *** numerical results reveal that THz radiation generation strongly depends on the chirp frequency parameter.A specific range of chirp frequencies exists for self-focusing as well as THz generation with a'turning point',where the THz emission reaches its maximum *** results show that the strength of self-focusing and consequently the generated THz radiation are reduced by increasing the density of doubly charged ionic species in the plasma due to the suppression of the nonlinear effects.

关键词： laser–plasma interaction THz generation chirped Gaussian laser beams

Effect of reverse flotation on magnetic separation concentrates

在线全文

学校读者我要写书评

暂无评论

International journal of Minerals,Metallurgy and Materials 2012年第8期19卷 669-674页

作者： s.O. Bada A.s. Afolabi M.j. Makhula school of Chemical & Metallurgical Engineering University of the Witwatersrand P/Bag X3 Wits 2050 Johannesburg South Africa Department of Mineral Processing Division Mintek Johannesburg South Africa Department of Civil and Chemical Engineering College of Science Engineering and Technology University of South Africa P/Bag X6 Florida 1710 Johannesburg South Africa

Reverse flotation studies on magnetite samples have revealed that the use of starch as a depressant of Fe-oxides has a hydrophilic effect on the surface of Fe-bearing silicates and significantly decreases Fe in the silica-rich stream when used in combination with an amine （Lilaflot D817M）. In this study, the effect of reverse flotation on the optimization of products obtained fi＇om magnetic separation was inves- tigated. Two different magnetic samples, zones 1 and 2, were milled to 〈75 btm and then subjected to low intensity magnetic separation （LIMs）. The LIMs test conducted on the 〈75 ~m shown an upgrade of 46.40wt% Fe, 28.40wt% siO2 and 2.61wt% MnO for zone 1 and 47.60wt% Fe, 29.17wt% siO2 and 0.50wt% MnO for zone 2. Further milling of the ore to 〈25 ~tm resulted in a higher magnetic-rich product after magnetic separation. Reverse flotation tests were conducted on the agitated magnetic concentrate feed, and the result shows a significant upgrade of Fe compared to that obtained from the non-agitated feed. Iron concentrations greater than 69%, and siO2 concentrations less than 2% with overall magnetite recoveries greater than 67% and 71% were obtained for zones 1 and 2, respectively.

关键词： magnetite flotation magnetic separation starch amines

Evaluation of the virulence of entomopathogenic fungus, Isaria fumosorosea isolates against subterranean termites Coptotermes spp.(Isoptera:Rhinotermitidae)

在线全文

学校读者我要写书评

暂无评论

journal of Forestry Research 2019年第1期30卷 213-218页

作者： j.j.jessica T.L.Peng A.s.sajap s.H.Lee s.A.syazwan Department of Forest Management Faculty of ForestryUniversiti Putra Malaysia (UPM) Faculty of Veterinary Medicine University Malaysia Kelantan Institute of Tropical Forestry and Forest Products Universiti Putra Malaysia (UPM) Mycology and Pathology Laboratory Forest Biodiversity Division Forest Research Institute Malaysia

The entomopathogenic fungus Isaria fumosorosea Wize, formerly known as Paecilomyces fumosoroseus is reported as a promising biocontrol agent for controlling subterranean termites, particularly those belonging to the family Rhinotermitidae. In Malaysia, the family Rhinotermitidae includes two species of subterranean termites with extremely high economic importance; namely Coptotermes curvignathus Holmgren, and the Asian sLubterranean Termite (Coptotermes gestroi Wasmann). To comprehend the potential control of this soil-dwelling fungus against these subterranean termites in Malaysia, an investigation was carried out by testing the pathogenecity of 11 isolates against these termite species. All isolates showed pathogenic potential against the termite (Mortality rate of C. curvignathus:84.4%; C. gestroi:67.3%). IsolatePF49 was the most effective against both species of termites and was further tested for its virulence and *** LC_(50) values of PF49 against C. curvignathus and *** were 7.55×103 and 1.09×102 conidia/ml,respectively. The average number of days required to complete the mycosis process in C. curvignathus and *** were 4.7 and 8 days, respectively. These fungi are believed useful for protecting living trees, plants, wood,wood structures, and other cellulosic materials susceptible to termite infestation and damage.

关键词： Biological control Entomopathogenic fungus subterranean termites Lethal concentration

PDE Constrained Optimization and Design of Frozen Mode Crystals

在线全文

学校读者我要写书评

暂无评论

Communications in Computational Physics 2008年第4期3卷 878-898页

作者： s.Chun j.s.Hesthaven Division of Applied Mathematics Brown UniversityProvidenceRI 02912USA.

We explore the use of PDE constrained nonlinear optimization techniques to optimize and design electromagnetic crystals which exhibit frozen mode *** is characterized by Van Hove singularities in the dispersion relation,e.g.,stationary reflection points and degenerate band edge ***,the optimization process modifies the dispersion relation by adjusting the geometries and material *** resulting algorithm is found to be capable of recovering all known crystal configurations as well as many new configurations,some of which display dramatically improved properties over previously used *** investigate both gyrotropic photonic crystals and degenerate band edge crystals as well as the more complex case of the oblique *** this latter case,we extend the investigation to the three-dimensional case to identify the first three-dimensional crystal exhibiting frozen mode behavior.

关键词： PDE constrained optimization method of matched asymptotics frozen mode photonic crystal.

Modeling of the Frozen Mode Phenomenon and its sensitivity Using Discontinuous Galerkin Methods

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

Communications in Computational Physics 2007年第4期2卷 611-639页

作者： s.Chun j.s.Hesthaven Division of Applied Mathematics Brown UniversityProvidenceRI 02912USA.

We investigate the behavior and sensitivity of the frozen mode phenomenon in finite structures with anisotropic materials,including both magnetic materials and non-normal *** studies are done by using a high-order accurate discontinuous Galerkin method for solving Maxwells equations in the time *** confirm the existence of the phenomenon also in the time-domain and study carefully the impact of the finite crystal on the frozen *** sets the stage for a thorough study of the robustness of the frozen mode phenomenon,resulting in guidelines for which design parameters are most sensitive and acceptable tolerances.

关键词： Discontinuous Galerkin method Maxwell equation photonic crystals frozen mode.