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Effects of forced aeration on community dynamics of free and attached bacteria in copper sulphide ore bioleaching

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international Journal of minerals,metallurgy and materials 2022年第1期29卷 59-69页

作者： Wei Chen Shenghua Yin i.m.S.K.ilankoon Key Laboratory of ministry of Education for High-Efficient mining and Safety of metal University of Science and Technology BeijingBeijing 100083China School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China Discipline of Chemical Engineering School of EngineeringMonash UniversityJalan Lagoon SelatanBandar SunwaySelangor Darul Ehsan 47500Malaysia

Bacterial community dynamics and copper leaching with applied forced aeration were investigated during low-grade copper sulphide bioleaching to obtain better bioleaching *** illustrated that appropriate aeration improved bacterial concentrations and leaching *** highest bacterial concentration and Cu^(2+)concentration after 14-d leaching were 7.61×10^(7) cells·mL^(−1) and 704.9 mg·L^(−1),respectively,at aeration duration of 4 h·d^(−1).The attached bacteria played a significant role during bioleaching from 1 to 7 ***,free bacteria dominated the bioleaching processes from 8 to 14 *** phenomenon was mainly caused by the formation of passivation layer through Fe3+hydrolysis along with bioleaching,which inhibited the contact between the attached bacteria and ***,16S rDNA analysis verified the effect of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans on the bioleaching *** results demonstrate the importance of free and attached bacteria in bioleaching.

关键词： attached bacteria bioleaching forced aeration free bacteria low-grade copper sulphide ore

Functional films based on mechanoactivated starch with prolonged release of preservative

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Food Bioscience 2022年第3期47卷 810-818页

作者： i.m.Lipatova A.A.Yusova L.i.makarova G.A.Krestov institute of Solution Chemistry of the Russian Academy of Sciences 1 Akademicheskaya St.Ivanovo153045Russia

Use of active edible films containing an antimicrobial agent-a new method of extending the shelf life of food *** the controlled release of the preservative from the film is an urgent *** work aims to introduce a new environmentally friendly process for the production of antifungal starch films with a prolonged release of a preservative using mechanoactivation in a rotor-stator device (RSD).Active films based on mechanoactivated starch hydrogels containing 0–5.0% (w/w) benzoic acid as a preservative and chitosan as a solubilizing additive (St-BA-Ch),as well as films containing sodium benzoate (St-SB) for comparison,were obtained by the casting *** were characterized using optical and atomic force microscopy,X-ray diffraction and tensile and moisture permeability testing *** was found that benzoic acid is present in the St-BА-Ch-films in the form of submicron ***-BА-Ch films showed greater tensile strength and a lower release rate of the preservative into model media compared to St-SB *** is established that mechanical activation of casting hydrogels in RSD allows increasing the strength films by an average of 2 times,as well as reducing the release rate of the preservative and the vapor permeability of the *** antifungal activity of the films was confirmed using Aspergillus *** developed active St-BА-Ch film can be recommended for use in the food industry to extend the shelf life of food products.

关键词： Starch films Benzoic acid Sodium benzoate mechanoactivation Rotor–stator device mechanical and barrier properties

Effect of magnesium and nickel coatings on the wetting behavior of alumina toughened zirconia by molten Al-mg alloy

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international Journal of minerals,metallurgy and materials 2012年第1期19卷 77-82页

作者： H. Sharifi A.R. Khavandi m. Divandari m.i. Hasbullah School of materials and metallurgical Engineering iran University of Science and Technology Department of material Engineering Faculty of mechanical Engineering University Teknologi malaysia

The wettability of alumina toughened zirconia （ZTA） by Al-mg alloy was investigated using the sessile drop technique. The ef fects of nickel coating, magnesium content, nitrogen atmosphere, and processing temperature on the contact angle between the molten alloy and the substrate were determined. Likewise, the effect of these factors on the wetting properties was studied. The results showed that the nickel coating on the ceramic substrate caused a significant reduction in solid/liquid surface energy and the contact angle decreased obvi- ously. The presence of magnesium in the molten aluminum alloy in nitrogen atmosphere reduced the contact angle effectively. The presence of magnesium in the alloy must be at a minimum amount of 2wt%-3wt% . moreover, it was suggested that some chemical reactions in the Al-mg-N system led to the production of mg3N2 and AlN compositions. These compositions improved the wetting properties of the systems by reducing the surface energy of the molten. it was shown that increasing the temperature is also an effective factor for the enhancement of wetting properties.

关键词： wetting coatings alumina zirconia ceramic materials composite materials

Production of porous silica by the combustion of rice husk ash for tundish lining

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Journal of University of Science and Technology Beijing 2008年第3期15卷 307-313页

作者： Y.m.Z.Ahmed E.m.Ewais Z.i.Zaki Central metallurgical Research and Development institute(CmRDi)

in order to study the production of porous silica compacts by the combustion of rice husk ash （RHA） for tundish lining, the experimental design technique was used to evaluate the effect of firing temperature, soaking time and compaction pressure on controlling both the porosity degree and compressive strength of rice husk ash compacts. The results revealed that while the porosity degree of the compacts decreased with the increase in the entire studied parameters, the compressive strength exhibited another trend especially at a lower soaking time. At a lower soaking time, the increase in firing temperature led to a slight decrease in compressive strength and then increasing thereafter. The porous silica compacts having 30% porosity and 〉 2.5 mPa compressive strength suitable for tundish lining could be obtained from the combustion of rice husk ash compacts.

关键词： porous silica rice husk ash tundish lining compressive strength porosity

Stellar Population Analysis of Galaxies based on Genetic Algorithms

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Chinese Journal of Astronomy and Astrophysics 2005年第4期5卷 347-355页

作者： Abdel-Fattah Attia H.A.ismail i.m.Selim A.m.Osman i.A.isaa m.A.marie A.A.Shaker National Research institute of Astronomy and Geophysics(NRiAG) 11421 HelwanCairoEgyptNational Research Institute of Astronomy and Geophysics(NRIAG)11421 HelwanCairoEgypt Cairo University Faculty of ScienceAstronomy DepartmentEgypt

We present a new method for determining the age and relative contribution of different stellar populations in galaxies based on the genetic *** apply this method to the barred spiral galaxy NGC 3384,using CCD images in U,B,V,R and i *** analysis indicates that the galaxy NGC 3384 is mainly inhabited by old stellar population(age〉10^9 yr).Some problems were encountered when numerical simulations are used for determining the contribution of different stellar populations in the integrated color of a *** results show that the proposed genetic algorithm can search efficiently through the very large space of the possible ages.

关键词： methods numerical-galaxies stellar population-galaxies individual(NGC 3384).

Targeting harmful effects of non-excitatory amino acids as an alternative therapeutic strategy to reduce ischemic damage

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Neural Regeneration Research 2025年第9期20卷 2454-2463页

作者： Victoria Jiménez Carretero irisÁlvarez-merz Jorge Hernández-Campano Sergei A.Kirov Jesús m.Hernández-Guijo Department of Pharmacology and Therapeutic School of MedicineUniv.Autónoma de MadridMadridSpain Ramón y Cajal institute for Health Research(iRYCiS) Neurobiology-Research ServiceHospital Ramón y CajalMadridSpain institute of Neurobiology Faculty of Mathematics and Natural SciencesHeinrich Heine University DüsseldorfDüsseldorfGermany Department of Neuroscience and Regenerative medicine&Department of Neurosurgery Medical College of Georgia at Augusta UniversityAugustaGAUSA

The involvement of the excitatory amino acids glutamate and aspartate in ce rebral ischemia and excitotoxicity is ***,the role of non-excitatory amino acids in brain damage following a stroke or brain trauma remains largely *** release of amino acids by necrotic cells in the ischemic core may contribute to the expansion of the *** findings indicated that the reversible loss of field excitato ry postsynaptic potentials caused by transient hypoxia became irreversible when exposed to a mixture of just four non-excitatory amino acids(L-alanine,glycine,L-glutamine,and L-serine)at their plasma *** amino acids induce swelling in the somas of neurons and astrocytes during hypoxia,along with permanent dendritic damage mediated by N-methyl-D-aspartate *** N-methyl-D-aspartate receptors prevented neuronal damage in the presence of these amino acids during *** is likely that astroglial swelling caused by the accumulation of these amino acids via the alanine-serine-cysteine transporter 2 exchanger and system N transporters activates volume-regulated anion channels,leading to the release of excitotoxins and subsequent neuronal damage through N-methyl-D-aspartate receptor ***,previously unrecognized mechanisms involving non-excitatory amino acids may contribute to the progression and expansion of brain injury in neurological emergencies such as stroke and traumatic brain *** these pathways co uld highlight new therapeutic targets to mitigate brain injury.

关键词： cell swelling N-methyl-D-aspartate receptor non-excitatory amino acids stroke synaptic transmission

Deuteron inelastic scattering on ^(6)Li and ^(7)Li nuclei within the three-body cluster model

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Chinese Physics C 2021年第1期45卷 286-296页

作者： m.V.Egorov V.i.Postnikov Federal State Unitary Enterprise"Russian Federal Nuclear"Center'Academician E.i.Zababakhin All-Russian Research institute of Technical Physics SnezhinskChelyabinsk Region.Russia and Physics FacultyTomsk State UniversityLenina ave.36Tomsk 634050Russia National Research Nuclear University mEPhi MoscowRussia

The problem of the deuteron interaction with lithium nuclei,treated as a system of two coupled pointlike clusters,is formulated to calculate the cross sections of the d+Li *** d+Li reaction mechanism is described using the Faddeev theory for the three-body problem of deuteron-nucleus *** theory is slightly extended for calculation of the stripping processes ^6Li(d,p)^7Li,^7Li(d,p)^8 ,^6Li(d,n)^7 Be,and ^7Li(d,n)^8 Be,as well as fragmentation reactions yielding tritium,a-particles,and continuous neutrons and protons in the initial deuteron kineticenergy region Ed=0.5-20 *** phase shifts found for d+^6Li and d+^7Li elastic scattering,as part of the simple optic model with a complex central potential,were used to find the cross sections for the 6^Li(d,ym)^8 and ^7Li(d,yE1)^9 Be radiation *** three-body dynamics role is also summarized to demonstrate its significant influence within the d+^7Li system.

关键词： deuteron-Li Faddeev equation inelastic scattering cluster model

GiS-based analysis of fault patterns in urban areas： A case study of irkutsk city, Russia

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Geoscience Frontiers 2016年第2期7卷 287-294页

作者： R.m. Lobatskaya i.P. Strelchenko irkutsk Research Technological University Irkutsk Russia

The capabilities of GiS in modeling fault patterns are explored for irkutsk city in East Siberia with implications for ground stability. The neotectonic structure of the area is visualized in three dimension （3D） taking into account fault dips, using the ArcGiS, Globalmapper and Paradigm Geophysical packages. The study area is divided into blocks of different size classes according to the length-based ranks of the bounding faults, which are of five classes distinguished with the equal interval method. The blocks show different deformation patterns, with different densities and strikes of crossing and bounding faults. The data are statistically processed using GiS to estimate the deformation degrees of blocks in arbitrary units per square kilometer using the attributes of rank and crossing/bounding position of faults and the size of blocks. The deformation degrees are then compared with available estimates of ground stability measured as a score of points corresponding to destabilizing factors. Although the comparison generally confirms some linkage between the deformation degree of blocks and their ground stability, the correlation is intricate and ambiguous. in order to enhance the advantages of GiS in building and analyzing 3D models of fault patterns for estimating ground stability and mitigating geological hazards, it is expected in the future to proceed from the reported initial step of visualization to more advanced analysis.

关键词： GiS 3D modeling Fault pattern Faults Blocks Ground stability

Effects of the phase variation and high-order momentum transfer components of NN amplitude on p-~4He elastic scattering

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Nuclear Science and Techniques 2018年第1期29卷 65-76页

作者： i.m.A.Tag-Eldin m.m.Taha S.S.A.Hassan Nuclear Experimental Physics Department Nuclear Research Center Atomic Energy Authority mathematics and Theoretical Physics Department Nuclear Research Center Atomic Energy Authority

Elastic scattering differential cross sections for a p- ~4He system are calculated within the framework of optical limit approximation of the Glauber multiple scattering model. Three different ranges for proton energy(E_(lab)), 19〈E_(lab)〈50 me V, 100≤E_(lab)≤1730 me V, and 45 ≤E_(lab)≤393 Ge V are considered. it is shown that the Pauli blocking fails to describe the data up to the proton energy, E_(lab)〈100 me V. For higher proton energies, a qualitative agreement is obtained. The observed elastic scattering differential cross section is nicely reproduced in the whole range of scattering angles in the center of mass system up to Θ_(c.m.)〈200° for 19〈E_(lab) ≤100 me V when the effect of both the nucleon–nucleon(NN) phase variation parameter γNN and higher-order momentum transfer components(λ_n; n = 1 and 2) of(NN) elastic scattering amplitude is included. in the range of 200 E_(lab) 1730 me V, introducing λ_n plays a significant role in describing the data up to the momentum transfer, q^2≤1:2(Ge V/c)~***, it is found that considering only the effect of phase variation parameter, cNN, improved the agreement in the region of minima for elastic scattering differential cross section for 45≤E_(lab)≤393 Ge V. The values of cNNand kn as a function of incident proton energies are presented.

关键词： Elastic scattering Optical limit approximation Glauber multiple scattering model