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Electrode-induced impurities in tin halide perovskite solar cell material CsSnBr_(3) from first principles

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npj Computational Materials 2021年第1期7卷 555-563页

作者： Yuhang Liang Xiangyuan Cui Feng Li Catherine Stampfl simon p.ringer Rongkun Zheng School of physics The University of SydneyNew South Wales 2006Australia School of Aerospace Mechanical and Mechatronic EngineeringThe University of SydneyNew South Wales 2006Australia

All-inorganic lead-free CsSnBr_(3)is attractive for applications in solar cells due to its nontoxicity and stability,but the device performance to date has been *** the intrinsic properties,impurities induced from electrodes may significantly influence the device ***,we systematically studied the stability,transition energy levels,and diffusion of impurities from the most commonly used electrodes(Au,Ag,Cu,graphite,and graphene)in CsSnBr_(3)based on density functional theory *** results reveal that,whereas graphite and graphene electrodes exhibit negligible influence on CsSnBr_(3)due to the relatively high formation energies for carbon impurities in CsSnBr_(3),atoms from the metal electrodes can effectively diffuse into CsSnBr_(3)along interstice and form electrically active impurities in CsSnBr_(3).In this case,a significant amount of donor interstitial impurities,such as Agti,Cuti,and Auti,will be formed under p-type conditions,whereas the Sn-site substitutional acceptor impurities,namely Au_(Sn)^(2-),Ag_(Sn)^(2-),and Cu_(Sn)^(2-),are the dominant impurities,especially under n-type *** particular,except for Auti,all these major impurities from the metal electrodes act as nonradiative recombination centers in CsSnBr_(3)and significantly degrade the device *** work highlights the distinct behaviors of the electrode impurities in CsSnBr_(3)and their influence on the related devices and provides valuable information for identifying suitable electrodes for optoelectronic applications.

关键词： stability perovskite halide

Correlation between precipitates evolution and mechanical properties of Al-Sc-Zr alloy with Er additions

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Journal of Materials Science & Technology 2022年第4期99卷 61-72页

作者： Li Liu Jian-Tang Jiang Xiang-Yuan Cui Bo Zhang Liang Zhen simon p.ringer School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China China-Ukraine Institute of Welding Guangdong Academy of SciencesGuangzhou 510651China School of Aerospace Mechanical and Mechatronic Engineeringand Australian Centre for Microscopy and MicroanalysisThe University of SydneyNew South Wales 2006Australia School of Materials Science and Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China

Correlation between precipitates evolution and mechanical properties of Al-Sc-Zr alloy with Er additions during isothermal ageing were investigated by microhardness measurements,transmission electron microscopy,atom probe tomography and density functional theory-based *** results demonstrate that the Er additions significantly improve the hardness during elevated temperature ageing,especially at 400℃.This is mainly because Er additions increase the nucleation rate of the Al_(3)(Er,Sc,Zr)precipitates,resulting in a higher density of fine and uniform dispersion of L1_(2)structured ***-principles calculations demonstrate that the second nearest neighboring solute-solute interactions for the species Sc,Zr and Er are energetically favored–a key feature to rationalize the observed precipitate structure and the underlying formation *** sequential formation of the core/shell precipitates in the Er-free alloy and core/double-shell precipitates in the Er-containing alloy arises due to the different solute-solute and solute-vacancy interaction energies,and the relative diffusivities of the Er,Sc and Zr species in *** results shed light on the beneficial effects of Er additions on the agehardening behavior of Al-Sc-Zr alloy and provide guidance for designing the ageing treatments for the Al-Sc-Zr(-Er)alloys.

关键词： Al alloys Isothermal ageing Microhardness Transmission electron microscopy Atom probe tomography First-principles calculations

微量钪对Al-15Ag合金时效特性与微观组织的影响

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稀有金属材料与工程 2004年第9期33卷 928-932页

作者：陈志国郑子樵 simon p.ringer 中南大学湖南长沙410083 Australian Key Centre for Microscopy and Microanalysis the University of Sydney NSW 2006Australia

通过时效硬化曲线测量及时效组织分析,研究了微量钪对Al-15Ag合金时效行为和显微组织的影响。在Al-15Ag合金中添加0.2%Sc(质量分数,下同),可以增强合金在190℃和350℃时效的时效硬化效果,延长峰时效的到达时间。微量钪的添加促使合金中... 详细信息

通过时效硬化曲线测量及时效组织分析,研究了微量钪对Al-15Ag合金时效行为和显微组织的影响。在Al-15Ag合金中添加0.2%Sc(质量分数,下同),可以增强合金在190℃和350℃时效的时效硬化效果,延长峰时效的到达时间。微量钪的添加促使合金中γ′相细小密集地析出,同时钪的存在减少了γ′相宽面上的位错台阶数。含钪Al-15Ag合金中γ′相长大过程比较缓慢的微观机理是微量钪的添加影响了合金中γ′相宽面上的台阶分布。

关键词：铝合金时效显微组织钪

Microstructural properties of over-doped GaN-based diluted magnetic semiconductors grown by MOCVD

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Journal of Semiconductors 2012年第7期33卷 16-19页

作者：陶志阔张荣修向前崔旭高李丽李鑫谢自力郑有炓郑荣坤 simon p.ringer Key Laboratory of Advanced photonic and Electronic Materials School of Electronic Science and EngineeringNanjing University College of Electronic Science and Engineering Nanjing University of Posts and Telecommunications Australia Key Center for Microscopy and Microanalysis University of Sydney

We have grown transition metal （Fe, Mn） doped GaN thin films on c-oriented sapphire by metal-organic chemical vapor deposition. By varying the flow of the metal precursor, a series of samples with different ion con- centrations are synthesized. Microstructural properties are characterized by using a high-resolution transmission electron microscope. For Fe over-doped GaN samples, hexagonal Fe3N clusters are observed with Fe3N （0002） parallel to GaN （0002） while for Mn over-doped GaN, hexagonal Mn6N2.58 phases are observed with Mn6N2.58（0002） parallel to GaN （0002）. In addition, with higher concentration ions doping into the lattice matrix, the partial lattice orientation is distorted, leading to the tilt orGaN （0002） planes. The magnetization of the Fe over-doped GaN sam- ple is increased, which is ascribed to the participation of ferromagnetic iron and Fe3N. The Mn over-doped sample displays very weak ferromagnetic behavior, which probably originates from the Mn6N2.58.

关键词： MOCVD DMS high-resolution TEM

Astrophysical constraints on the proton-to-electron mass ratio with FAST

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Research in Astronomy and Astrophysics 2019年第2期19卷 15-24页

作者： Xi Chen simon p.Ellingsen Ying Mei Center for Astrophysics Guangzhou University Shanghai Astronomical Observatory Chinese Academy of Sciences School of physical Sciences University of Tasmania

That the laws of physics are the same at all times and places throughout the Universe is one of the basic assumptions of physics. Astronomical observations provide the only means to test this basic assumption on cosmological time and distance scales. The possibility of variations in the dimensionless physical constant μ-the proton-to-electron mass ratio, can be tested by comparing astronomical measurements of the rest frequency of certain spectral lines at radio wavelengths with laboratory determinations. Different types of molecular transitions have different dependencies on μ and so observations of two or more spectral lines towards the same astronomical source can be used to test whether there is any evidence for either temporal or spatial changes in the physical fundamental constants. μ will change if the relative strength of the strong nuclear force compared to the electromagnetic force varies. Theoretical studies have shown that the rotational transitions of some molecules which have transitions in the frequency range that will be covered by FAST(e.g., CH_3 OH, OH and CH) are sensitive to changes in μ. A number of studies looking for possible variations in μ have been undertaken with existing telescopes, however, the greater sensitivity of FAST means it will open new opportunities to significantly improve upon measurements made to *** this paper, we discuss which molecular transitions and sources(both in the Galaxy and external galaxies)are likely targets for providing improved constraints on μ with FAST.

关键词： ISM:molecules radio lines:ISM techniques:radial velocities elementary particles

Application of Multimedia and Internet Technology in Learning Mould Design

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厦门大学学报（自然科学版） 2002年第S1期41卷 295-296页

作者： simon S p Shum Department of Multimedia and Internet Technology

With the use of multimedia which combines the use o f text, sound, images, motion video and animation, it is more efficient for studen ts to learn mould design interactively. A program is created using several multi media software to simulate the mechanism of moulding processes in order to let s tudents understand the concept of mould design. In addition, students can even access the program through the Internet. Therefore, the software is defined as Multimedia and Internet Technology (MIT) program. The MIT program consists of four sections: (i) simulation of mould mechanisms, ( ii) cooling system, (iii) material information and (iv) games for tutorials. Sec tion One covers the basic operations of different types of moulds such as two-p late mould, three-plate mould, split mould, side-core mould and mould with und ercuts. Section Two introduces different types of cooling systems such as bubble r, baffle, cooling circuits, etc. Section Three provides some useful material in formation for mould design. Section Four contains games of matching mould compon ents, mould design problem finding and multiple choice questions to test student s how much they understand mould design concept. Multimedia is highly effective particularly in teaching and learning. It changes the nature of learning itself. It makes reading dynamic by giving words an impo rtant new dimension. It allows students to see, hear and do simultaneously, thus significantly reducing average learning time. Furthermore, through cooperative learning on Internet, students can access the program, share data or search info rmation anytime anywhere. Therefore, Multimedia and Internet Technology is one o f the vital aspects to speed up the realization of information age in society.

关键词： Application of Multimedia and Internet Technology in Learning Mould Design

Identification of Differentially Senescing Mutants of Wheat and Impacts on Yield,Biomass and Nitrogen partitioning

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Journal of Integrative plant Biology 2012年第8期54卷 555-566页

作者： Adinda p.Derkx simon Orford simon Griffiths M.John Foulkes Malcolm J. Hawkesford plant Biology and Crop Science Department Rothamsted ResearchHarpendenHertfordshireAL5 2JQUK Division of plant&Crop Sciences School of BiosciencesUniversity of NottinghamSutton Bonington CampusNr LoughboroughLE12 5RDUK John Innes Centre Norwich Research ParkColneyNorwich NR4 7UHUK

Increasing photosynthetic capacity by extending canopy longevity during grain filling using slow senescing stay-green genotypes is a possible means to improve yield in wheat. Ethyl methanesulfonate （EMS） mutated wheat lines （Triticum aestivum L. cv. paragon） were screened for fast and slow canopy senescence to investigate the impact on yield and nitrogen partitioning. Stay-green and fast-senescing lines with similar anthesis dates were characterised in detail. Delayed senescence was only apparent at higher nitrogen supply with low nitrogen supply enhancing the rate of senescence in all lines. In the stay-green line 3 （SG3）, on a whole plant basis, tiller and seed number increased whilst thousand grain weight （TGW） decreased; although a greater N uptake was observed in the main tiller, yield was not affected. In fast-senescing line 2 （FS2）, yield decreased, principally as a result of decreased TGW. Analysis of N-partitioning in the main stem indicated that although the slow-senescing line had lower biomass and consequently less nitrogen in all plant parts, the proportion of biomass and nitrogen in the flag leaf was greater at anthesis compared to the other lines; this contributed to the grain N and yield of the slow-senescing line at maturity in both the main tiller and in the whole plant. A field trial confirmed senescence patterns of the two lines, and the negative impact on yield for FS2 and a positive impact for SG3 at low N only. The lack of increased yield in the slow-senescing line was likely due to decreased biomass and additionally a possible sink limitation.

关键词： Wheat senescence stay-green grain-filling yield nitrogen.

Quantification of hookworm ova from wastewater matrices using quantitative pCR

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Journal of Environmental Sciences 2017年第7期29卷 231-237页

作者： pradip Gyawali Warish Ahmed Jatinder p.Sidhu paul Jagals simon Toze CSIRO Land and Water Ecosciences Precinct School of public Health The University of Queensland

A quantitative pCR（q pCR） assay was used to quantify Ancylostoma caninum ova in wastewater and sludge *** estimated the average gene copy numbers for a single ovum using a mixed population of *** average gene copy numbers derived from the mixed population were used to estimate numbers of hookworm ova in *** seeded and unseeded wastewater and sludge *** newly developed qp CR assay estimated an average of3.7 × 10~3 gene copies per ovum,which was then validated by seeding known numbers of hookworm ova into treated *** qp CR estimated an average of（1.1 ± 0.1）,（8.6 ± 2.9）and（67.3 ± 10.4） ova for treated wastewater that was seeded with（1 ± 0）,（10 ± 2） and（100 ± 21）ova,*** further application of the q pCR assay for the quantification of *** ova was determined by seeding a known numbers of ova into the wastewater *** qp CR results indicated that 50%,90% and 67% of treated wastewater（1 L）,raw wastewater（1 L）and sludge（~4 g） samples had variable numbers of *** gene *** conversion of the q pCR estimated gene copy numbers to ova for treated wastewater,raw wastewater,and sludge samples,had an average of 0.02,1.24 and 67 ova,*** result of this study indicated that qp CR can be used for the quantification of hookworm ova from wastewater and sludge samples;however,caution is advised in interpreting qp CR generated data for health risk assessment.

关键词： Wastewater matrices Quantitative pCR Hookworm ova Health risks

Optimal harvesting for a single-species population governed by Gompertz law:Influence of environmental fluctuation and limited harvesting capacity

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International Journal of Biomathematics 2019年第2期12卷 115-142页

作者： p.D.N.Srinivasu simon D.Zawka Sri Sathya Sai University for Human Excellence Navanihala Village Okali PostKamalapur Taluk Gulbarga DistrictKarnataka 585313India Department of Mathematics Andhra University Visakhapatnam 530003India Department of Mathematics Ar ba Minch University Arba MinchEthiopia

This work presents an optimal harvesting problem associated with a single-species population governed by Gompertz law in a seasonally fluctuating *** influence of environmental fluctuation is accommodated by choosing the coefficients in the differential equation to be periodic functions with the same period and restriction on the harvesting effort is accommodated by considering binding constraints on the control ***,a linear optimal control problem has been considered where the state dynamics is governed by Gompertz equation and the control variable is subject to the binding *** the help of maximum principle and the concept of blocked intervals,an optimal periodic solution has been obtained which is followed by the construe tion of optimal solution using the theory of most rapid *** results of the study are demonstrated through numerical simulations.

关键词： Optimal harvesting Gompertz equation seasonality binding constraint blocked intervals