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Enhanced tensile properties in a Mg-6Gd-3Y-0.5Zr alloy due to hot isostatic pressing(HIP)

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Journal of Materials Science & Technology 2019年第9期35卷 1860-1868页

作者： B. Zhoua d.Wu R.S.Chen En-hou Han The Group of Magnesium Alloys and Their applications Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026China

Hot isostatic pressing (HIP) was applied to Mg-6Gd-3Y-0.5Zr (GW63) alloy to reduce shrinkage porosity, thus, to enhance the integrity and reliability of castings. during HIP process, shrinkage porosity was closed by grain compatible deformation and subsequent diffusion across the bonding interface. The amount of initial shrinkage porosity was the key factor for shrinkage porosity closure. HIP was testified to be effective on shrinkage porosity reduction in GW63 alloy due to its relatively narrow solidification range and resultant low content of initial shrinkage porosity in most sections, leading to higher tensile properties both in as-cast and cast-T6 condition. The improvement in tensile properties was mainly because of shrinkage porosity reduction and resultant effective rare-earth (RE) elements homogenization and precipitation strengthening.

关键词： Hot isostatic pressing Mg-Gd-Y-Zr Shrinkage porosity reduction Tensile properties

Broadband Vibrational Cooling of Cold Cesium Molecules： Theory and Experiments

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Chinese Journal of Chemical Physics 2009年第2期22卷 149-156页

作者： d. Sofikitis A. Fioretti S. Weber M. Viteau A. Chotia R. Horchani M. Allegrini B. Chatel d. Comparat P. Pillet Laboratoire Aimé Cotton CNRS Université Paris-Sud Bat. 505 91405 Orsay France Laboratoire Collisions Agrégats Réactivité (UMR 5589 CNRS-Université Paul Sabatier Toulouse 3) IRSAMC Toulouse France CNISM Dipartimento di Fisica Universita di Pisa Largo Pontecorvo 356127 PISA Italy

The use of a broadband, frequency shaped femtosecond laser on translationally cold cesium molecules has recently demonstrated to be a very efficient method of cooling also the vibrational degree of freedom. A sample of cold molecules, initially distributed over several vibrational levels, has thus been transfered into a single selected vibrational level of the singlet X^1∑g ground electronic state. Our method is based on repeated optical pumping by laser light with a spectrum broad enough to excite all populated vibrational levels but limited in its frequency bandwidth with a spatial light modulator. In such a way we are able to eliminate transitions from the selected level, in which molecules accumulate. In this paper we briefly report the main experimental results and then address, in a detailed way by computer simulations, the perspectives for a ＂complete＂ cooling of the molecules, including also the rotational degree of freedom. Since the pumping process strongly depends on the relative shape of the ground and excited potential curves, ro-vibrational cooling through different excited states is theoretically compared.

关键词： Cold molecule Optical pumping Pulse .shaping Ultrashort pulse Laser cooling

Crowd-sourcing materials-science challenges with the NOMAd 2018 Kaggle competition

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npj Computational Materials 2019年第1期5卷 150-160页

作者： Christopher Sutton Luca M.Ghiringhelli Takenori Yamamoto Yury Lysogorskiy Lars Blumenthal thomas Hammerschmidt Jacek R.Golebiowski Xiangyue Liu Angelo Ziletti Matthias Scheffler Fritz Haber Institute of the Max Planck Society BerlinGermany Research Institute for Mathematical and Computational Sciences(RIMCS) YokohamaJapan ICAMS Ruhr-Universität BochumBochumGermany EPSRC Centre for doctoral Training on Theory and Simulation of Materials Department of PhysicsImperial College LondonLondonUK thomas Young Centre for Theory and Simulation of Materials Department of MaterialsImperial College LondonLondonUK

A public data-analytics competition was organized by the Novel Materials discovery(NOMAd)Centre of Excellence and hosted by the online platform Kaggle by using a dataset of 3,000(Al_(x)GayIn_(1-x-y))_(2)O_(3) *** aim was to identify the best machinelearning(ML)model for the prediction of two key physical properties that are relevant for optoelectronic applications:the electronic bandgap energy and the crystalline formation ***,we present a summary of the top-three ranked ML *** first-place solution was based on a crystal-graph representation that is novel for the ML of properties of *** second-place model combined many candidate descriptors from a set of compositional,atomic-environment-based,and average structural properties with the light gradient-boosting machine regression *** third-place model employed the smooth overlap of atomic position representation with a neural *** Pearson correlation among the prediction errors of nine ML models(obtained by combining the top-three ranked representations with all three employed regression models)was examined by using the Pearson correlation to gain insight into whether the representation or the regression model determines the overall model *** relatively decorrelated models(based on the Pearson correlation)leads to an even higher prediction accuracy.

关键词： energy prediction overlap

Graphene-platinum nanocomposite as a sensitive and selective voltammetric sensor for trace level arsenic quantification

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International Journal of Smart and Nano Materials 2014年第1期5卷 17-32页

作者： R.Kempegowda d.Antony P.Malingappa department of Chemistry Bangalore UniversityCentral College CampusBangalore 560001India Raman Research Institute C.V.Raman AvenueBangalore 560080India

A simple protocol for the chemical modification of graphene with platinum nanoparticles and its subsequent electroanalytical application toward sensitive and selective determination of arsenic has been *** modification was carried out by the simultaneous and sequential chemical reduction of graphene oxide and hexachloroplatinic acid in the presence of ethylene glycol as a mild reducing *** synthesized graphene-platinum nanocomposite(Gr-nPt)has been characterized through infrared spectroscopy,x-ray diffraction study,field emission scanning electron microscopy and cyclic voltammetry(CV)*** and square-wave anodic stripping voltammetry have been used to quantify *** proposed nanostructure showed linearity in the concentration range 10-100 nM with a detection limit of 1.1 *** proposed sensor has been successfully applied to measure trace levels of arsenic present in natural sample matrices like borewell water,polluted lake water,agricultural soil,tomato and spinach leaves.

关键词： arsenic graphene-platinum nanocomposite chemical modification square-wave anodic stripping voltammetry spinach leaves

NUMERICAL SIMULATION OF MOLTEN POOL ANd CONTROL STRATEGY OF KISS POINT IN A TWIN-ROLL STRIP CASTING PROCESS

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Acta Metallurgica Sinica(English Letters) 2008年第6期21卷 459-468页

作者： G.M. Cao C.G. Li Z. Y. Liu d. Wu G.d. Wang X.H. Liu State Key Laboratory of Rolling ＆ Automation Northeastern University Shenyang 110004 China

Coupled turbulent flow, temperature fields of the twin-roll casting strip process were simulated by three-dimensional finite element method. Based on the heat balance calculation and using inverse methods between the simulations and real experiments, the relational models among casting speed, location, and coefficient of heat transfer between molten metal and rolls in different regions are given. In the simulation, the calculated surface temperatures are in good agreement with the measured values. An on-line model of kiss point is derived by simulations and the geometry of molten pool, corresponding control strategy is also proposed.

关键词： Twin-roll strip casting Coupled temperature and flow field Numerical simulation Kiss point Control strategy

Neuromorphic devices based on fluorite-structured ferroelectrics

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InfoMat 2022年第12期4卷 1-32页

作者： dong Hyun Lee Geun Hyeong Park Se Hyun Kim Ju Yong Park Kun Yang Stefan Slesazeck thomas Mikolajick Min Hyuk Park department of Materials Science and Engineering&Inter-University Semiconductor Research Center College of EngineeringSeoul National UniversitySeoulRepublic of Korea Research Institute of Advanced Materials Seoul National UniversitySeoulRepublic of Korea NaMLab gGmbH DresdenGermany Institute of Engineering Research Seoul National UniversitySeoulRepublic of Korea

A continuous exponential rise has been observed in the storage and processing of the data that may not curtail in the foreseeable *** required data processing speed and power consumption are restricted by the buses between the logic and memory devices that are characteristic of the von Neumann computing ***-mimicking neuromorphic computing has garnered considerable academic and industrial interest to resolve these ***,devices based on emerging nonvolatile memories capable of mimicking the behaviors of synapses and neurons,which are the main elements in biological computing systems(brains),are attracting significant interest from the device *** the discovery of ferroelectricity in fluorite-structured oxides,such as HfO2 and ZrO2,which are compatible with the state-of-the-art complementary-metal-oxide-semiconductor processes,ferroelectric devices have rapidly evolved as the main direction of these research and development *** science related to fluorite-structured ferroelectrics has been intensively studied over the last *** present,the focus is gradually moving to practical applications,including neuromorphic computing and advanced classical processing or memory units in the conventional von Neumann ***,despite its rapid development,the wealth of recent progress in neuromorphic computing devices based on fluorite-structured ferroelectrics has not been reviewed and *** progress report comprehensively reviews and systemizes the recent progress in artificial synaptic and spiking neuron devices for neuromorphic computing based on fluorite-structured ferroelectrics.

关键词： ferroelectrics hafnia neuromorphic computing semiconductor devices

Mouse models of medulloblastoma

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Chinese Journal of Cancer 2011年第7期30卷 442-449页

作者： Paul A.Northcott Sidney Croul Michael d.Taylor Arthur and Sonia Labatt Brain Tumor Research Center Hospital for Sick Children

Medulloblastoma is the most common malignant pediatric brain tumor. despite its prevalence and importance in pediatric neuro-oncology, the genes and pathways responsible for its initiation, maintenance, and progression remain poorly understood. Genetically engineered mouse models are an essential tool for uncovering the molecular and cellular basis of human diseases, including cancer, and serve a valuable role as preclinical models for testing targeted therapies. In this review, we summarize how such models have been successfully applied to the study of medulloblastoma over the past decade and what we might expect in the coming years.

关键词：小鼠模型母细胞遗传工程人类疾病脑肿瘤发病率小儿神经

Magnetic Properties and Coercivity of MnGa Films deposited on different Substrates

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Journal of Materials Science & Technology 2017年第3期33卷 291-294页

作者： J.N.Feng W.Liu W.J.Gong X.G.Zhao d.Kim C.J.Choi Z.d.Zhang Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Powder and Ceramics division Korea Institute of Materials Science

MnGa films were grown by magnetron sputtering on thermally oxidized Si（Si/SiO2） and glass substrates. Films grown on single-crystal Si（100） substrate with different underlayers were prepared for comparison. It is found that the Si/SiO2 substrate is more suitable for growing high-coercivity MnGa films than the glass substrate, which is the result of the isolated-island-like growth. A coercivity of 9.7 kOe can be achieved for the 10 nm MnGa films grown on Si/SiO2 substrate at substrate temperature TS of 450 °*** experimental conditions are specified by changing the thickness of the MnGa films and the temperature of the substrates.

关键词： Atomic force microscopy Coercivity Magnetic properties Magnetron sputtering Thin film

Association between water related factors and active trachoma in Hai district, Northern Tanzania

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Infectious diseases of Poverty 2012年第1期1卷 92-98页

作者： Michael J Mahande Humphrey d Mazigo Eliningaya J Kweka Community Health department KCM College of Tumaini UniversityPO Box 2240MoshiTanzania department of Medical Parasitology and Entomology Catholic University of Health and Allied SciencesP.O.Box 1464MwanzaTanzania Tropical Pesticides Research Institute Division of Livestock and Human Disease vector controlPO Box 3024ArushaTanzania

Background:Trachoma is widely distributed in sub-Saharan Africa and is mainly associated with poor water ***,these associations have never been demonstrated in some of the communities,especially in northern *** cover that gap,the present case control study was conducted to assess the association of water related factors,general hygiene and active trachoma among preschool and school age children in Hai district,northern ***:Families reported to use>60 litres of water per day were less likely to have active disease(OR=0.4,95%CI:0.1-0.3;Pd to households collecting≤60 *** risk of having trachoma increased with increase in distance to the water point(OR=6.5,95%CI;1.8-16.7;P=0.003).Households members who reported to used number of preschool children in the household was also associated with increased risk of active trachoma by 2.46 ***:Improving water supply near the households and providing public health education focusing on improving households socio-economic status and individual hygiene especially in pre-school children in part will help to reduce the prevalence of the *** addition,integrating public health education with other interventions such as medical interventions remains important.

关键词： Trachoma Water Hygiene Tanzania