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Rare-earth free sensitizer in NaLuCrF_4:Er upconversion material

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Journal of Rare Earths 2019年第4期37卷 345-349页

作者： Bui The Huy Zayakhuu Gerelkhuu The-Long Phan ngo Tran Yong-IllLee Institute of Research and Development Duy Tan University Department of Chemistry Changwon National University Department of Physics Hankuk University of Foreign Studies

Upconversion phosphors are known as a material system that can convert near-infrared light into visible/ultraviolet emissions by sequentially absorbing multiple photons. The studies on upconversion materials often use two rare earth(RE) ions as a sensitizer-activator pair. We investigated the influences on luminescence intensity depending on Cr-doping content(x) of hexagonal NaLu_(0.98-x)Cr_xF4 Er_(0.02)(x = 0-0.9)upconversion material by substituting Lu^(3+) ions with Cr^(3+)in the absence of Gd^(3+). The change in upconversion luminescence intensity appears with saddle-like shape. We suggest that Cr^(3+) ions play the dual role as a constituent in host lattice and a sensitizer in the upconversion process. Optimal conditions for gaining the strongest upconversion emission correspond to x = 0.3-0.5, where there are effective energy transfers between Cr^(3+) and Er^(3+) ions and Cr-Er dimers. Apart from these values, the emission intensity decreases rapidly which can be ascribed to the absence of multiple-photon absorption for the case of low Cr^(3+) contents, and to the coupling between Cr^(3+) and/or Er^(3+) ions for the case of high Cr^(3+)contents. Magnetization and electron-spin-resonant measurements were performed to understand the correlation between the optical and magnetic properties.

关键词： Upconversion materials Sensitizer Transition metal ions Magnetism

The band structures of some transition metals and their NaCl-type compounds

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Chinese Journal of Chemistry 1996年第5期14卷 385-392页

作者： Cai, sh Liu, CW CHINESE ACAD SCI FUJIAN INST RES STRUCT MATTERSTATE KEY LAB STRUCT CHEMFUZHOU 350002FUJIANPEOPLES R CHINA

The band structures of Group IVB (Ti, Zr, Hf), VB (V, Nb, Ta) and VIE (Cr, Mo, W) transition metals and some of their carbides and nitrides (TiN, ZrN, HfN, VC, NbC, TaC, VN, NbN, TaN) with NaCl-type (B1-type) structure have been calculated by using the tight-binding method within the Extended Huckel approximation (EHT). The energy bands, densities of states and crystal orbital overlap populations are given. The relationship between the bonding properties and the superconducting transition temperatures (T-c) of them is discussed. The influences of various kinds of metallic atoms and changes of bond lengths on T-c are also discussed.

关键词： transition metals and their NaCl-type compounds tight-binding energy band calculation superconducting transition temperatures

Kerosene-alumina nanofluid flow and heat transfer for cooling application

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Journal of Central South University 2016年第4期23卷 983-990页

作者： M.Mahmoodi sh.Kandelousi Department of Aerospace Engineering Malek-Ashtar University of Technology Department of Mechanical Engineering Babol University of Technology

Kerosene-alumina nanofluid flow and heat transfer in the presence of magnetic field are studied. The basic partial differential equations are reduced to ordinary differential equations which are solved semi analytically using differential transformation method. Velocity and temperature profiles as well as the skin friction coefficient and the Nusselt number are determined analytically. The influence of pertinent parameters such as magnetic parameter, nanofluid volume fraction, viscosity parameter and Eckert number on the flow and heat transfer characteristics is discussed. Results indicate that skin friction coefficient decreases with increase of magnetic parameter, nanofluid volume fraction and viscosity parameter. Nusselt number increases with increase of magnetic parameter and nanofluid volume fraction while it decreases with increase of Eckert number and viscosity parameter.

关键词：流体流动纳米流体氧化铝煤油 Nusselt数常微分方程应用冷却

Analysis of maximum pressure in VVER1000/V446 reactor containment for LOCA and MSLB

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Nuclear Science and Techniques 2017年第9期28卷 109-118页

作者： sh. sheykhi S. Talebi Department of Energy Engineering and Physics Amirkabir University of Technology (Tehran Polytechnic) 424 HafezAvenue Tehran 15875-4413 Iran

The highest thermal-hydraulic pressure in the containment occurs when reactor coolant in the first loop and steam in the secondary loop discharge simultaneously,and when the maximum amount of energy from reactor unit enters to containment volume. In this paper, we investigate temperature and pressure variations in the VVER 1000 containment compartments owing to concurrent break in the pipelines of the primary and secondary loops. A two-phase, multicellular model is applied in the presence of non-condensable gases. Convection and conduction through the main heat structures inside the containment are also considered. The predicted results agree well with available data. Maximum values of pressure and temperature in the containment are then calculated and compared to the design values. If LOCA and MSLB occur simultaneously, the maximum pressure would exceed the design value and integrity of the containment would be threatened.

关键词：压力分析失水事故反应堆控制容积最大能量压力变化模型应用内部控制

Recent Advances of Chimp Optimization Algorithm:Variants and Applications

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Journal of Bionic Engineering 2023年第6期20卷 2840-2862页

作者： Mohammad sh.Daoud Mohammad shehab Laith Abualigah Mohammad Alshinwan Mohamed Abd Elaziz Mohd Khaled Yousef shambour Diego Oliva Mohammad AAlia Raed Abu Zitar College of Engineering Al Ain University112612Abu DhabiUnited Arab Emirates College of Computer Sciences and Informatics Amman Arab UniversityAmman11953Jordan Computer Science Department Prince Hussein Bin Abdullah Faculty for Information TechnologyAl Al-Bayt UniversityMafraq25113Jordan Hourani Center for Applied Scientific Research Al-Ahliyya Amman UniversityAmman19328Jordan MEU Research Unit Middle East UniversityAmman11831Jordan Applied Science Research Center Applied Science Private UniversityAmman11931Jordan School of Computer Sciences Universiti Sains Malaysia11800Pulau PinangMalaysia Faculty of Information Technology Applied Science Private UniversityAmman 11931Jordan Department of Mathematics Faculty of ScienceZagazig UniversityZagazig 7120001Egypt The Custodian of the Two Holy Mosques Institute for Haj and Umrah Research Umm Al-Qura UniversityMakkah 24382Saudi Arabia Depto.de Innovacio'n Basada en la Informacio'n y el Conocimiento Universidad de GuadalajaraCUCEI45129 GuadalajaraMexico Cyber Security Department Faculty of Science and Information TechnologyAl Zaytoonah University of JordanAmman 11733Jordan Sorbonne Center of Artificial Intelligence Sorbonne University-Abu Dhabi38044 Abu DhabiUnited Arab Emirates School of Engineering and Technology Sunway University Malaysia27500Petaling JayaMalaysia

Chimp Optimization Algorithm(ChOA)is one of the recent metaheuristics swarm intelligence *** has been widely tailored for a wide variety of optimization problems due to its impressive characteristics over other swarm intelligence methods:it has very few parameters,and no derivation information is required in the initial ***,it is simple,easy to use,flexible,scalable,and has a special capability to strike the right balance between exploration and exploitation during the search which leads to favorable ***,the ChOA has recently gained a very big research interest with tremendous audiences from several domains in a very short ***,in this review paper,several research publications using ChOA have been overviewed and ***,introductory information about ChOA is provided which illustrates the natural foundation context and its related optimization conceptual *** main operations of ChOA are procedurally discussed,and the theoretical foundation is ***,the recent versions of ChOA are discussed in detail which are categorized into modified,hybridized,and paralleled *** main applications of ChOA are also thoroughly *** applications belong to the domains of economics,image processing,engineering,neural network,power and energy,networks,*** of ChOA is also *** review paper will be helpful for the researchers and practitioners of ChOA belonging to a wide range of audiences from the domains of optimization,engineering,medical,data mining,and *** well,it is wealthy in research on health,environment,and public ***,it will aid those who are interested by providing them with potential future research.

关键词： Artificial intelligence Nature-inspired optimization algorithms Chimp optimization algorithm Optimization problems

Transesterification catalyzed by samarium tri-2-propoxide

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Chinese Journal of Chemistry 1997年第1期15卷 90-93页

作者： Fu, XL Wu, sh Department of Chemistry Fudan University Shanghai 200433 Chino

A facile method for transesterification was reported. Under catalysis by samarium tri‐2‐propoxide tbe yields of transesterification are good to excellent, and this reaction has surprising selectivity and mildness du... 详细信息

关键词： transesterification samarium tri-2-propoxide catalysis

Full Scale Explosive Tests in Woomera, Australia

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Transactions of Tianjin University 2006年第B9期12卷 56-60页

作者： GUPTA A MENDIS P LUMANTARNA R ngo T APTES Group Department of Civil and Environmental EngineeringThe University of Melbourne

Two large explosion trials (5 000 kg TNT and 500 kg ANFO) were conducted in Woomera, Australia in April/May 2006. Advance Protective Technologies for Engineering Structures (APTES) group tested 2 large single-storey concrete modules with individual components such as doors, windows and tiled panels. A description of the trial and details of various modules tested in these trials are presented in the paper. Numerical modelling and simulations are performed using computer programs, CONWEP, AIR3D and AUTODYN. A comparison of the pressure time histories obtained using these codes is made along with the concluding remarks.

关键词：爆破试验混凝土模块爆炸压力模型保护技术模拟试验

Facile hydrothermal synthesis of flower-like hematite microstructure with high photocatalytic properties

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Journal of Advanced Ceramics 2015年第1期4卷 61-64页

作者： Timur sh.ATABAEV Department of Physics and Astronomy Seoul National UniversityGwanak-guSeoul 151-747Republic of Korea

A flower-like hematite microstructure has been successfully prepared by a facile hydrothermal synthesis method without using any organic solvents or *** is revealed that the flower-like hematite microstructure consists of well-crystallized nanorods with the average diameter of about 100±15 nm and average length of about 900±100 nm growing from the centers.A possible growth mechanism of the flower-likeα-Fe_(2)O_(3)microstructure is proposed and *** photocatalytic properties of the synthesized flower-like hematite nanostructure are evaluated using the degradation of rhodamine B in aqueous solution.

关键词： hematite nanostructure hydrothermal synthesis

Traumatic Rupture of the Diaphragm: Retrospective Study of 27 Cases Operated in Three Hospitals in Yaoundé (Cameroon)

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Surgical Science 2022年第4期13卷 207-215页

作者： Guy Aristide Bang Georges Bwele Motto Marie Ange ngo Yamben Christel Teddy Chappi Joseph Cyrille Chopkeng Daniel Biwole Biwole Bernadette ngo Nonga Departement of Surgery Yaoundé University Teaching Hospital Yaoundé Cameroon Faculty of Medicine and Biomedical Sciences University of Yaoundé I Yaoundé Cameroon Department of Digestive Central Hospital of Yaoundé Yaoundé Cameroon Department of Orthopaedic Surgery and Traumatology Yaoundé Emergency Centre Yaoundé Cameroon

Background: Traumatic ruptures of the diaphragm (TRD) are serious lesions that are often part of polytrauma. They pose a real diagnostic and therapeutic challenge in a disadvantaged environment such as ours. Methods: We conducted a descriptive observational study covering a period of 11 years in 3 referral hospitals in the city of Yaoundé (Cameroon). All patients who had undergone surgery for a traumatic rupture of the diaphragm between January 1, 2011 and December 31, 2020, and whose outcome within 30 days of surgery was known were included. Results: A total of 27 patients were collected. Their mean age was 36.4 ± 19.7 years. There was a strong male predominance with 22 cases (81.5%). The TRD occurred mainly after an assault (n = 9, 33.3%), was mainly on the left side (n = 25, 92.6%) and was most often part of a polytrauma (n = 17, 62.9%). The lesions associated with TRD were mainly visceral (n = 11) and bony (n = 6). The diagnosis was made preoperatively in only 13 patients (48.1%). The average length of the diaphragmatic breach was 6.4 ± 4.5 cm and a simple suture was most often used for the repair (26 cases or 96.3%). Four osteosynthesis procedures were performed at the same time as the diaphragmatic repair. The morbidity rate was 51.9%, with surgical site infection as the main complication. Six deaths (22.2%) were recorded;septic shock was the main etiology (n = 4). Conclusion: The hospital incidence of TRD remains low in our context. These lesions remain associated with significant morbidity and mortality and require a multidisciplinary approach.

关键词： Traumatic Rupture of the Diaphragm Morbidity Mortality Polytrauma