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Stabilization of mixed-halide lead perovskites under light by photothermal effects

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Journal of Energy Chemistry 2021年第12期30卷 8-11,I0001页

作者： Juvinch r.Vicente Martin E.Kordesch Jixin Chen Department of Chemistry and Biochemistry Ohio UniversityAthensOH 45701United States Nanoscale and Quantum Phenomena Institute Ohio UniversityAthensOH 45701United States Department of Chemistry University of the Philippines VisayasMiagaoIloilo 5023Philippines Department of Physics and Astronomy Ohio UniversityAthensOH 45701United States

Mixed-halide lead perovskites(MHLPs) are semiconductor materials with bandgaps that are tunable across the visible spectrum and have seen promising applications in photovoltaics and ***, their segregation into phases with enriched halide components, under resonant light illumination and/or electric field, have hindered their practical applications. Herein, we demonstrate the stabilization of the MHLP photoluminescence(PL) peak as a function of their excitation *** effect is associated with the phase segregation of MHLPs and their subsequent remixing by photothermal heating. We conclude that the balance between these opposing processes dictates the equilibrium PL peak of the MHLPs. The findings in this work could serve as a potential approach to obtain MHLP with stable emission peaks under operating conditions.

关键词： Perovskites Phase segregation Photothermal Solar cells LEDs

Thermal and Electrical Properties of Sn-Zn-Bi Ternary Soldering Alloys

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Materials Sciences and Applications 2015年第11期6卷 1008-1013页

作者： M. A. Wadud M. A. Gafur M. r. Qadir M. o. rahman Department of Physics Jahangirnagar University Savar Bangladesh PP&PDC BCSIR Dhaka Bangladesh

Sn-Zn based solder is a possible replacement of Pb solder because of its better mechanical properties. The alloys need to be studied and explored to get a usable solder alloy having better properties. In this work, eutectic Sn-9Zn and three Tin-Zinc-Bismuth ternary alloys were prepared and investigated their thermal and electrical properties. Thermo-mechanical Analysis and Differential Thermal Analysis were used to investigate thermal properties. Microstructural study is carried out with Scanning Electron Microscope. The alloys have single melting point. The co-efficient of thermal expansion and co-efficient of thermal contraction varies with alloy composition and temperature range. Electrical conductivity changes with Bi addition.

关键词： Lead Free Solder Alloy Eutectic Alloy DTA TMA Conductivity

Bemisia tabaci Phylogenetic Groups in India and the relative Transmission Efficacy of Tomato leaf curl Bangalore virus by an Indigenous and an Exotic Population

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Journal of Integrative Agriculture 2012年第2期11卷 235-248页

作者： r V Chowda-reddy M Kirankumar Susan E Seal V Muniyappa Girish B Valand M r Govindappa John Colvin Agriculture Health and Environment GroupNatural Resources InstituteUniversity of Greenwich at MedwayChatham MaritimeKentME4 4TBUnited Kingdom Southern Crop Protection and Food research Centre London-N5V 4T3Canada Department of Plant Pathology University of Agricultural SciencesBangalore-560 065India Department of Plant Pathology Gujarat Agricultural UniversityAnand 388110GujaratIndia

Bemisia tabaci adults from various host-plant species were collected from 31 regions across India.266 *** samples were first screened by rAPD-PCr to examine molecular variability and to select individuals with different ***-plant and region of collection were then used to select 25 individuals for PCr amplification and sequencing of their partial mitochondrial cytochrome oxidase subunit one（mtCoI）*** comparisons with mtCoI consensus sequences showed that the majority of these samples had 〈3.5% sequence divergence from groups currently termed Asia I,Asia II-5,Asia II-7,and Asia *** biotype-B *** from India clustered into the Middle East-Asia Minor 1 group.A new group of *** from Coimbatore,collected from pumpkin,was related most closely to the Asia I group（6.2% sequence divergence from the consensus Asia I sequence）.To increase our understanding of the epidemiology of tomato leaf curl disease（ToLCD）and the key *** genetic groups involved in virus spread,the indigenous Asia I and the exotic biotype-B population from South India were used to carry out transmission experiments using Tomato leaf curl Bangalore virus（ToLCBV）.The acquisition access periods（AAP）,inoculation access periods（IAP）,latent periods（LP）,and ToLCBV transmission efficiencies of the two populations were compared and the biotype-B had the more efficient transmission *** results are discussed in relation to recent changes in the epidemiology of tomato leaf curl disease in South India.

关键词： begomoviruses mitochondrial cytochrome oxidase whitefly Bemisia tabaci virus-vector relationships epidemiology

Exploring the vacuum ultraviolet photochemistry of astrochemically important triatomic molecules

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National Science review 2023年第8期10卷 243-259页

作者： Yao Chang Michael N.r. Ashfold Kaijun Yuan Xueming Yang State Key Laboratory of Molecular reaction Dynamics and Dalian Coherent Light Source Dalian Institute of Chemical Physics Chinese Academy of Sciences School of Chemistry University of Bristol University of Chinese Academy of Sciences Hefei National Laboratory Department of Chemistry College of Science Southern University of Science and Technology

The recently constructed vacuum ultraviolet(VUV) free electron laser(FEL) at the Dalian Coherent Light Source(DCLS) is yielding a wealth of new and exquisitely detailed information about the photofragmentation dynamics of many small gas-phase molecules. This review focuses particular attention on five triatomic molecules—H2o, H2S, Co2, oCS and CS2. Each shows excitation wavelength-dependent dissociation dynamics, yielding photofragments that populate a range of electronic and(in the case of diatomic fragments) vibrational and rotational quantum states, which can be characterized by different translational spectroscopy methods. The photodissociation of an isolated molecule from a well-defined initial quantum state provides a lens through which one can investigate how and why chemical reactions occur, and provides numerous opportunities for fruitful, synergistic collaborations with high-level ab initio quantum chemists. The chosen molecules, their photofragments and the subsequent chemical reaction networks to which they can contribute are all crucial in planetary atmospheres and in interstellar and circumstellar environments. The aims of this review are 3-fold: to highlight new photochemical insights enabled by the VUV-FEL at the DCLS, notably the recently recognized central atom elimination process that is shown to contribute in all of these triatomic molecules; to highlight some of the potential implications of this rich photochemistry to our understanding of interstellar chemistry and molecular evolution within the universe; and to highlight other and future research directions in areas related to chemical reaction dynamics and astrochemistry that will be enabled by increased access to VUV-FEL sources.

关键词： vacuum ultraviolet photochemistry photodissociation free electron laser interstellar chemistry chemistry of planetary atmospheres

Antifertility effects of methanolic pod extract of Albizzia lebbeck (L.) Benth in male rats

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Asian Journal of Andrology 2004年第2期6卷 155-159页

作者： r. S. Gupta J. B. S.Kachhawa r. Chaudhary reproduction Physiology Section Department of Zoology University of Rajasthan Jaipur-302 004 IndiaReproduction Physiology Section Department of Zoology University of Rajasthan Jaipur-302 004 IndiaReproduction Physiology Section Department of Zoology University of Rajasthan Jaipur-302 004 India

Aim: To evaluate the antifertility activity of the methanolic pod extract of Albizzia lebbeck (L.) Benth in male albino rats. Methods: The methanolic pod extract of Albizzia lebbeck was administrated orally for 60 days at 50, 100 and 200 mg·kg-1·day-1 to male albino rats. Sperm motility and density in cauda epididymides were assessed. Biochemical and histological analysis were performed in blood samples and reproductive organs. results: A. lebbeck pod extract brought about a significant decrease in the weights of testis, seminal vesicles, epdidymis and ventral prostate. The sperm motility and density were significantly reduced. There was a marked reduction in the numbers of primary spermatocytes, secondary spermatocytes and spermatids. The Sertoli cell count as well as its cross sectional surface area were significantly decreased. The Leydig cell nuclear area and the number of mature Leydig celis were also significantly decreased. The protein, glycogen and cholesterol content of the testis, the fructose in the seminal vesicles and protein in the epididymis were significantly decreased. The rBC and WBC counts, haemoglobin, haematocrit and blood sugar were within the normai range. Conclusion: The methanolic extract of A. lebbeck pods causes spermatogenic arrest in male albino rats.

关键词： Albizzia lebbeck sertoli celis spermatogonia spermatocytes leydig celis

Tetrapartite entanglement measures of generalized GHZ state in the noninertial frames

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Chinese Physics B 2022年第3期31卷 170-176页

作者： Qian Dong r.Santana Carrillo Guo-Hua Sun Shi-Hai Dong Centro de Investigacion en Computacion Instituto Politecnico NacionalUPALMCDMX 07738Mexico Catedratica CoNACyT Centro de Investigacion en ComputacionInstituto Politenico NacionalUPALMCDMX 07738Mexico research Center for Quantum Physics Huzhou UniversityHuzhou 313000China Laboraorio de Informacion Cuantica CIDETECInstituto Poitenico NacionalUPALMCDMX 07700Mexico

Using a single-mode approximation, we carry out the entanglement measures, e.g., the negativity and von Neumann entropy when a tetrapartite generalized GHZ state is treated in a noninertial frame, but only uniform acceleration is considered for simplicity. In terms of explicit negativity calculated, we notice that the difference between the algebraic average π_(4) and geometric average Π_(4) is very small with the increasing accelerated observers and they are totally equal when all four qubits are accelerated simultaneously. The entanglement properties are discussed from one accelerated observer to all four accelerated observers. It is shown that the entanglement still exists even if the acceleration parameter r goes to infinity. It is interesting to discover that all 1-1 tangles are equal to zero, but 1-3 and 2-2 tangles always decrease when the acceleration parameter γ increases. We also study the von Neumann entropy and find that it increases with the number of the accelerated observers. In addition, we find that the von Neumann entropy S_(ABCDI), S_(ABCIDI), S_(ABICIDI) and S_(AIBICIDI) always decrease with the controllable angle θ, while the entropies S_(3-3 non), S_(3-2 non), S_(3-1 non) and S_(3-0 non) first increase with the angle θ and then decrease with it.

关键词： tetrapartite generalized GHZ state entanglement measures dirac field noninertial frames

An approach to delineate groundwater recharge potential sites in Ambalantota,Sri Lanka using GIS techniques

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Geoscience Frontiers 2016年第1期7卷 115-124页

作者： i.p.senanayake d.m.d.o.k.dissanayake b.b.mayadunna w.l.weerasekera Department of Earth resources Engineering University of Moratuwa MoratuwaSri Lanka

The demand for fresh water in Hambantota District, Sri Lanka is rapidly increasing with the enormous amount of ongoing development projects in the region. Nevertheless, the district experiences periodic water stress conditions due to seasonal precipitation patterns and scarcity of surface water ***, management of available groundwater resources is critical, to fulfil potable water requirements in the area. However, exploitation of groundwater should be carried out together with artificial recharging in order to maintain the long term sustainability of water resources. In this study, a GIS approach was used to delineate potential artificial recharge sites in Ambalantota area within Hambantota. Influential thematic layers such as rainfall, lineament, slope, drainage, land use/land cover, lithology, geomorphology and soil characteristics were integrated by using a weighted linear combination method. results of the study reveal high to moderate groundwater recharge potential in approximately 49% of Ambalantota area.

关键词： GIS Groundwater recharge Water management Weighted overlay Sri Lanka

A strategy for designing stable nanocrystalline alloys by thermo-kinetic synergy

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Journal of Materials Science & Technology 2020年第8期36卷 21-31页

作者： H.r.Peng B.S Liu F.Liu State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an710072China School of Materials and Chemical Engineering Xi’an Technological UniversityXi’an710021China Analytical and Testing Center Northwestern Polytechnical UniversityXi’an710072China

Aiming to design stable nanocrystalline(NC)materials,so far,it has been proposed to construct nanostructure stability maps in terms of thermodynamic parameters,while kinetic stabilization has seldom been considered,despite the synergy of thermodynamics and ***,the thermodynamically stabilized NC materials may be easily subjected to grain growth at high temperatures due to the weakly kinetic *** from the thermo-kinetic synergy,a stabilization criterion is proposed as a function of intrinsic solute parameters(*** activation energy for bulk diffusion and the segregation enthalpy),intrinsic solvent parameters(*** intrinsic activation energy for GB migration and the GB energy)and processing parameters(*** grain size,the temperature and the solute concentration).Using first-principles calculations for a series of combinations between fifty-one substitutional alloying atoms as solute atoms and Fe atom as fixed solvent atom,it is shown that the thermal stability neither simply increases with increasing the segregation enthalpy as expected by thermodynamic stabilization,nor monotonically increases with increasing the activation energy for bulk diffusion as described by kinetic *** combination of thermodynamic and kinetic contributions,the current stabilization criterion evaluates quantitatively the thermal stability,thus permitting convenient comparisons among NC materials involved by various combinations of the solute atoms,the solvent atoms,or the processing *** of this thermo-kinetic stabilization criterion has been tested by current experiment results of Fe-Y alloy and previously published data of Fe-Ni,Fe-Cr,Fe-Zr and Fe-Ag alloys,etc.,which opens a new window for designing NC materials with sufficiently high thermal stability and sufficiently small grain size.

关键词： Thermo-kinetic Synergy Criterion Thermal stability Nanocrystalline materials

Analysis of Bio-inspired Fishbone Based Corrugated rib for Adaptive Camber Morphing

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Journal of Bionic Engineering 2023年第3期20卷 1083-1102页

作者： r.Jini raj J.Bruce ralphin rose A.Vasudevan Department of Mechanical Engineering Anna University Regional CampusTirunelveli627007India Saveetha School of Engineering SIMATSChennai600124India

Bioinspired active camber morphing is an innovative solution for the aerodynamic performance enhancement of flight vehicles such as Micro Aerial Vehicles(MAVs)and Unmanned Aerial Vehicles(UAVs).In the present article,a bio-inspired Fish Bone Active Camber(FishBAC)corrugated rib design concept with and without a spine for an Unmanned Aerial Vehicle(UAV)is *** wing model is composed of multiple corrugated ribs and a splitted spar for connecting each *** rib geometry is subjected to static structural analysis using ANSYS Finite Element Analysis(FEA)module under the unit load *** deformation modes are first extracted from the solution of the wind tunnel test and the elastically deformed NACA 4412 profile will be used to perform Fluid-Structure Interaction(FSI)studies as a partly coupled *** corrugated rib with spine design is a stable structure as inspired from nature species that can withstand elastic and inertial *** fluid dynamics(CFD)simulation is performed to compute the coefficient of lift(Cl),coefficient of drag(Cd)at different Angle of Attack(AoA)for a modified NACA 4412 airfoil and the pressure loads acting on the deformed shape is *** Cl obtained for the modified airfoil at lower AoA is about 60–80%higher and the maximum Cl(Clmax)is 62%higher than the baseline *** Cd of modified airfoil is reduced about 20%at the AoAα=3°as compared with the baseline *** proposed corrugated rib structure has been successfully 3D printed with Polylactic Acid plus(PLA+)material and the wind tunnel testing is done to validate the Cl,Cd values obtained through CFD simulations and the results are presented.

关键词： Bioinspired design Active morphing Fish bone Wind tunnel CFD