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Development of novel rare earth doped fluoride and oxide scintillators for two-dimensional imaging

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Journal of Rare Earths 2011年第12期29卷 1178-1182页

作者： A.Yoshikawa T.Yanagida Y.Yokota K.Kamada N.Kawaguchi K.Fukuda A.Yamazaki K.Watanabe A.Uritani T.Iguchi G.Boulon M.Nikl institute for Materials Research Tohoku University New Industry creation Hatchery Center Tohoku University R&D Center Tokuyama CorporationShibuya 3-ChomeShibuya-ku Nagoya University Furo-choChikusa-ku Physical Chemistry of Luminescent Materials(LPCML) University of Lyon institute of Physics AS cr

Two topics were focused. The first one was about the gamma-ray scintillator, Pr^3＋：Lu3Al5O12 （LuAG）. The second one was about neutron scintillator, Ce^3＋：^6LiCaAlF6 and Eu^2＋：^6LiCaAlF6 （^6LiCAF）. Those scintillators have been developed very recently for modem imaging applications in the medical and homeland security fields. In both cases, the rare earth ions are playing the crucial role as emission centers. Pr^3＋ in LuAG provided fast 5d→4f transition providing noticeably shorter decay time than that of Ce^3＋. Among several candidate hosts, LuAG showed the best performance. Bulk crystal growth, basic scintillation properties, two-dimensional gamma-ray imaging and positron emission mammography （PEM） application were demonstrated. Due to the international situation, the homeland security was compromized by illicit traffic of explosives, drugs, nuclear materials, etc. and the ways to its improvement became an important R＆D topic. For this purpose the Ce and Eu doped LiCAF appeared competitive candidates. Especially, when substitution of 3He neutron detectors was considered, the discrimination ability of gamma-ray from alpha-ray was important. Bulk crystal growth, basic scintillation properties and two-dimensional neutron imaging were demonstrated.

关键词： Scintillator gamma-ray detection neutron detection oxide fluoride Ce, Eu rare earth

Overview of the HiLASE project: high average power pulsed DPSSL systems for research and industry

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High Power Laser Science and Engineering 2014年第2期2卷 1-10页

作者： M.Divoky M.Smrz M.Chyla P.Sikocinski P.Severova O.Novak J.Huynh S.S.Nagisetty T.Miura J.Pila O.Slezak M.Sawicka V.Jambunathan J.Vanda A.Endo A.Lucianetti D.Rostohar P.D.Mason P.J.Phillips K.Ertel S.Banerjee C.Hernandez-Gomez J.L.Collier T.Mocek HiLASE Institute of Physics AS CR v.v.i. Na Slovance 2 182 21 Prague Czech Republic STFC Rutherford Appleton Laboratory Didcot OX11 0QX United Kingdom

An overview of the Czech national R&D project HiLASE(High average power pulsed laser) is presented. The project focuses on the development of advanced high repetition rate, diode pumped solid state laser(DPSSL) systems with energies in the range from mJ to 100 J and repetition rates in the range from 10 Hz to 100 kHz. Some applications of these lasers in research and hi-tech industry are also presented.

关键词： DPSSL Yb3+:YAG thin-disk multi-slab pulsed high average power laser

Numerical Simulation of Separated Flows in Channels

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Journal of Thermal Science 2012年第2期21卷 145-153页

作者： Petr Louda Jaromír Príhoda Petr Sváek Karel Kozel Czech Technical University in Prague Fac. of Mechanical Engineering Karlovo nám. 13 CZ-121 35 Praha 2 institute of Thermomechanics AS cr v.v.i. Dolejkova 5 CZ-182 00 Praha 8

The work deals with numerical modelling of turbulent flows in channels with an expansion of the cross-section where flow separation and reattachment occur. The performance of several eddy viscosity models and an explicit algebraic Reynolds stress model (EARSM) is studied. The used test cases are flows in channels with various backward facing steps where the step is perpendicular or inclined and the top wall is parallel or deflected. Furthermore, a channel with the circular ramp is considered. The numerical solution is achieved by the finite volume method or by the finite element method. The results of both numerical approaches are compared.

关键词： backward facing step flow EARSM model SST model

Comparative chemical sensor for detection of chromium(Ⅵ) in aqueous solution

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Optoelectronics Letters 2025年第1期21卷 21-27页

作者： Sura H.AL-REKABI A.A.ALWAHIB Electrical Technique Department Al Suwayrah Technical Institute Middle Technical University Laser and Optoelectronics Department University of Technology-Iraq

A process for purifying aqueous solutions containing heavy and toxic metals such as chromium（cr） has been investigated. One of the extremely harmful pollutants in rivers and seawater is the heavy metal ions due to their direct impacts on human, animals and plants are hexavalent cr（Ⅵ）. Consequently, highly sensitive sensor to detect cr is essential. Surface plasmon resonance（SPR） technique has attracted huge research interest in detecting heavy metals specifically. In this study, three types of prism-based SPR sensor, gold（Au）/silver（Ag）, Au/polyaniline（PANI） and Au/titanium dioxide（TiO2） nanostructured films, are investigated as potential sensing material to detect the presence of cr（Ⅵ） ions in water. The base Au layer with thickness of 48.3 nm is deposited on a glass slide for all sensors. For Au/Ag, Au/PANI nanofibers and Au/TiO2sensor films, the cr（Ⅵ） concentration is varied from 1 ppm to 15 ppm with sensitivity of 0.270 °ppm-1, 0.082 °ppm-1and 0.039 °ppm-1, respectively. Based on these results, the Au/PANI nanofibers are the most sensitive to cr（Ⅵ） among the tested sensing materials.

关键词： Titanium dioxide

Transient vibration of thin viscoelastic orthotropic plates

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Acta Mechanica Sinica 2011年第1期27卷 98-107页

作者： J.Soukup F.Vale J.Volek J.Skoilas Jan Evangelista Purkyně University in ústí nad Labem Faculty of Production Technology and Management Department of Machinery and Mechanics Centre of Material Diagnostics Institute of Thermomechanics AS CR v.v.i Academy of Sciences Czech Republic

This article deals with solutions of transient vibration of a rectangular viscoelastic orthotropic thin 2D plate for particular deformation models according to Flu¨gge and *** linear model,a general standard viscoelastic body,of the rheologic properties of a viscoelastic material was *** time and coordinate curves of the basic quantities displacement,rotation,velocity,stress and deformation are *** results obtained by an approximate analytic method are compared with numerical results for 3D plate generated by FEM application and with experimental investigation.

关键词： Transient vibration thin plate Orthotropic General viscoelastic standard solid.

Generation of high-energy neutrons with the 300-ps-laser system PALS

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High Power Laser Science and Engineering 2014年第3期2卷 72-77页

作者： J.Krsa D.Klír A.Velyhan E.Krousky M.Pfeifer K.Rez J.Cikhardt K.Turek J.Ullschmied K.Jungwirth institute of Physics AS CR182 21 Prague 8Czech Republic Czech Technical University in Prague FEE166 27 PragueCzech Republic Nuclear Physics institute AS CR180 00 Prague 8Czech Republic institute of Plasma Physics AS CR182 00 Prague 8Czech Republic

The laser system PALS,as a driver of a broad-beam ion source,delivered deuterons which generated neutrons with energies higher than 14 Me V through the 7Li(d,n)8 Be *** with sub-Me V energy were accelerated from the front surface of a massive CD2 target in the backward direction with respect to the laser beam ***,neutrons were emitted from the primary CD2 target and a secondary Li F *** total maximum measured neutron yield from 2D(d,n)3He,7Li(d,n)8Be,12C(d,n)13N reactions was ～3.5(±0.5) × 108 neutrons/shot.

关键词： beam–target fusion deuterons laser ion sources lithium neutrons

High-dense nanocrystalline W-based alloy prepared by hot isostatic pressing with uniform microstructure, ultrahigh hardness and good thermal stability

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Tungsten 2025年第1期 120-136页

作者： Zao-Ming Wu Lin He Lin-Sen Ye Xiao-Feng Yang Jia-Jia Zhang Hong-Bo Lei institute of Materials China Academy of Engineering Physics

High-density uniform microstructure nanocrystalline W-10wt.% cr-5wt.% Y（W-10cr-5Y） alloy with an average grain size of 85 nm and a relative density of 99.8% was successfully prepared.W-cr-Y alloys with different amounts of second-phase particles were prepared by high-energy ball milling and hot isostatic pressing *** effects of composition design,ball milling parameters,and sintering parameters on the microstructure of W-cr-Y alloys were studied.A feasible technology for controlling the synthesis of high-density nanocrystalline W-based alloys has been *** microstructure analysis of nanocrystalline W-10cr-5Y alloy shows that there are two types of doping in the second phase:intergranular doping and intragranular *** "uniform distribution YOx-rich particles" effectively suppresses the grain growth of W and leads to the formation of nanocrystalline W-10cr-5Y alloy.W-10cr-5Y has an ultra-high hardness,with a Vickers hardness of 1312±12 kgf·***-temperature annealing treatment shows that W-10cr-5Y has good thermal stability at 1000 and1100℃,as demonstrated by the comparison of Vickers hardness and grain size between annealed and unannealed alloys.

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Comparison of （η^6－Fluoroarene）tricarbonylchromium Complexes with Their Chloro－analogs in Radical Aromatic Substitutions

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Chinese Journal of Chemistry 2003年第7期21卷 797-800页

作者：林和春杨立李超忠 State Key Laboratory of Applied Chemistry Lanzhou UniversityLanzhouGansu 730000China State Key Laboratory of Applied Chemistry Lanzhou UniversityLanzhouGansu 730000China Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai 200032China Reactions of fluoroarene-Cr(CO)_3 complexes with SmI_2 andcarbonyl compounds in THF/HMPA at-40--60℃affordedthe corresponding radical aromatic substitution products in highyield. Compared to the corresponding chloroarene-Cr.(CO)_3complexes fluoroarene-Cr(CO)_3 complexes showed a higher ef-ficiency and slightly lower regioselectivity.

Reactions of fluoroarene-cr(CO)3 complexes with SmI2 andcarbonyl compounds in THF/HMPA at - 40- -60℃ affordedthe corresponding radical aromatic substitution products in high yield. Compared to the corresponding chloroarene-cr(CO)3 complexes, fluoroarene-cr(CO)3complexes showed a higher efficiency and slightly lower regioselectivity.

关键词： radical substitution arenetricarbonylchromium complex

Improving ecosystem services in farmlands:beginning of a long-term ecological study with restored flower-rich grasslands

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Ecosystem Health and Sustainability 2022年第1期8卷 399-405页

作者： András Báldi Raoul Pellaton Áron Domonkos Bihaly Viktor Szigeti Eszter Lellei-Kovács András Máté Miklós Sárospataki Zoltán Soltész LászlóSomay AnikóKovács-Hostyánszki Lendület Ecosystem Services Research Group Institute of Ecology and BotanyCentre for Ecological ResearchVácrátótHungary Department of Zoology and Ecology Institute of Wildlife Management and Nature ConservationHungarian University of Agriculture and Life SciencesGödöllőHungary Dorcadion Ltd KecskemétHungary

Biodiversity declines in an unprecedented way,mostly due to land use *** interventions proved to be one of the most effective tools to halt the decline,especially in ecosystems such as agricultural ***-based,locally adapted recommendations on grassland restoration,however,are often missing,so we present a novel approach for such interventions that can be implemented anywhere and that are based on scientific *** a recently started long-term field ecological study,we established 0.5 ha wildflower parcels,using a diverse local seed mixture of 32 insect-visited plant species in Central European agricultural landscapes in *** focus is on the landscape-scale effects of this ecological intensification on ecosystem services such as crop yield,pollination and pest control,and the long-term monitoring of the successional *** aim is to showcase an effective restoration protocol that could serve as a model for future farm management,and provide much-needed evidence for policy on landscape ecological restoration of international relevance.

关键词： Ecological intensification field experiment protocol restoration wildflower strip