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Thermoluminescence characterization of natural and synthetic irradiated Ce-monazites

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journal of Rare Earths 2024年第4期42卷 643-650页

作者： V.Correcher C.Boronat j.Garcia-Guinea j.F.Benavente T.Rivera-Montalvo CIEMAT Av.Complutense 4028040MadridSpain MNCN-CSIC J.Gutierrez Abascal 228006MadridSpain Instituto Politécnico Nacional CICATA-IPNAv.Legaria 694Mexico City11500Mexico

The thermoluminescence(TL)emission of synthetic and natural Ce-monazites was characterized here to determine the potential application in the identification of microscopic defects from a qualitative point of view trying to link each TL peak to a chemical-physical *** kinetic parameters that lead the luminescence processes were calculated by means of variable heating rate and computing glow curve deconvolution methods and allow identifying three groups of components at~90,130 and 290℃(for the mineral sample)and~90,170,220,270 and 320℃(for the synthetic CePO_(4):Nd_(0.20),La_(0.25)).The main differences appreciated in these complex TL curves are mainly due to(i)the content of impurities(natural sample contains lanthanides as well as U 0.60%and Th 5.22%)and(ii)the degree of crystallinity of the samples which is directly related to the type of impurities(synthetic monazite relies only on Nd and La).The behavior of the dose response in the range of 1-8 Gy is similar for both samples;the TL intensity increases linearly as the dose increases without changes in the position of the maxima,denoting first-order kinetic luminescence *** peak could be mostly associated with structural defects(i.e.,phase transitions),chemical reactions(i.e.,Ce3+?Ce4+redox reaction,dehydration or dehydroxylation processes)or intrinsic defects(i.e.,frenkel defects,ODCs or NBOHCs).

关键词： Thermoluminescence Kineticparameters Phosphate Ce-monazite Defects Rare earths

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jNS:惊心动魄的取栓过程

中国卒中杂志 2018年第11期13卷 1182-1183页

作者：杨中华 frenkel M B RENFROW j j SINGH j 首都医科大学附属北京天坛医院神经病学中心脑血管病中心神经重症医学科北京100070 不详

2018年journalofNeurosurgery杂志报道了1例血管内取栓联合外科手术治疗颈动脉闭塞和大脑中动脉栓塞的病例。患者71岁,男性。既往高脂血症、高血压和阿司匹林过敏史。患者在医院餐厅中突然跌倒,出现左侧偏瘫和忽视,美国国立卫生研究院... 详细信息

2018年journalofNeurosurgery杂志报道了1例血管内取栓联合外科手术治疗颈动脉闭塞和大脑中动脉栓塞的病例。患者71岁,男性。既往高脂血症、高血压和阿司匹林过敏史。患者在医院餐厅中突然跌倒,出现左侧偏瘫和忽视,美国国立卫生研究院卒中量表(National Institutes of Health stroke scale,NIHSS)评分18分。

关键词：国立卫生研究院卒中量表取栓大脑中动脉栓塞颈动脉闭塞 NIHSS 手术治疗高脂血症阿司匹林

THERMOML:EMERGING IUPAC STANDARD FOR THERMODYNAMIC DATA COMMUNICATIONS

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THERMOML:EMERGING IUPAC STANDARD FOR THERMODYNAMIC DATA COMM...

Influence of Drying Methods on Fractal Geometric Characteristics of Mesoporous Silica Aerogels

40th IUPAC Congress

作者： M. frenkel R. D. Chirico V. V. Diky Q. Dong K. N. Marsh j. H. Dymond W. A. Wakeham S. E. Stein E. Koenigsberger Thermodynamics Research Center （TRC Group） Physical and Chemical Properties DivisionNational Institute of Standards and TechnologyBoulderCO 80305-3328USA Thermodynamics Research Center （TRC Group） Physical and Chemical Properties DivisionNational Institute of Standards and TechnologyBoulderCO 80305-3328USA Thermodynamics Research Center （TRC Group） Physical and Chemical Properties DivisionNational Institute of Standards and TechnologyBoulderCO 80305-3328USA Thermodynamics Research Center （TRC Group） Physical and Chemical Properties DivisionNational Institute of Standards and TechnologyBoulderCO 80305-3328USA Department of Chemical and Process Engineering University of Canterbury Chemistry Department University of Glasgow Glasgow G12 8QQUK School of Engineering Sciences University of Southampton HighfieldSouthampton SO17 1BJUK Physical and Chemical Properties Division National Institute of Standards and TechnologyGaithersburgMD 20899- 8380USA Division of Science and Engineering School of Mathematical and Physical SciencesMurdoch UniversityMurdochWA 6150Australia

来源： cnki会议评论

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journal of Wuhan University of Technology(Materials Science) 2013年第3期28卷 476-482页

作者：赵善宇 XU Haixun WANG Lijiu j William Suggs School of Environmental and Safety Engineering Changzhou University School of Civil and Hydraulic Engineering Dalian University of Technology Department of Chemistry Brown University

Chemical modification/ambient drying method and freeze drying method were introduced to research the synthesis of mesoporous silica aerogels. By analyzing N2 gas adsorption/desorption isotherms, the fractal geometric characteristics of gels were focused. The overall surface fractal dimensions were determined by analyzing N2 gas adsorption branch and a frenkel-Halsey-Hill （FHH） equation was empolyed to determine surface fractal dimension Df It is found that, during ambient drying process, VTMCS/VWetgel ratio plays a crucial role in the changes of geometric feature, the key point is 50%, when the ratio is lower, and surface roughness increases with the ratio, when it exceeds 50%, the surface is almost unaffected by the modification. While freeze drying always tends to get larger Df freeze drying process could cause a rough surface of the gels. Compared with traditional porosity and specific surface area analyses, fractal geometry may be expected to be favorable for mesoporous structural analyses of materials.

关键词： silica aerogel N2 gas adsorption surface fractal dimension mesoporous structure

ELECTRICAL TRANSPORT PROPERTIES OF PRISTINE AND IODINE DOPED POLYETHERIMIDES

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Chinese journal of Polymer Science 2011年第5期29卷 586-596页

作者： j.K.Quamara Randhir Singh B.K.Kaushik Physics Department National Institute of TechnologyKurukshetra 136119India

Electrical conduction behavior of pristine and iodine doped polyetherimides （PEI） has been investigated under both transient and steady state conditions in the operating temperature range 50-200℃ at various electric fields of 12-60 kV/cm. The transient currents show the hyperbolic decay character, and the decay exponent p （a measure of current decay rate） decreases with temperature （T） and doping concentration. The origin of transient currents has been attributed to the dipolar nature of carbonyl （〉C：O） groups and the ether linkages present in the main chain of PEI. The low field steady state conduction is ohmic in nature. The magnitudes of ionic jump distance （a） values do not favor an ionic type of conduction as a possible conduction mechanism in pristine as well as iodine doped PEI. The Schottky coefficients estimations do not show the possibility of Schottky type or Poole-frenkel type conduction mechanisms in the low temperature region （〈 120℃）, however, in the high temperature region （〉 120℃） there is a certain possibility of Poole- frenkel type conduction mechanism in both pristine and iodine doped samples. The dual slope in the lg/versus 1/T curves for iodine doped samples indicates the presence of more than one type of trapping levels.

关键词： Transient currents Electrical conduction Polyetherimide.

Defect production and atomic mixing by displacement cascades in Ni_3Al

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Science China(Technological Sciences) 1997年第5期40卷 553-560页

作者：高飞王天民 A.F.Calder D.j.Bacon Department of Materials Science Lanzhou University Lanzhou 730000 ChinaDepartment of Materials Science Lanzhou University Lanzhou 730000 ChinaDepartment of Materials Science and EngineeringUniversity of LiverpoolLiverpool L69 3BXUKDepartment of Materials Science and EngineeringUniversity of LiverpoolLiverpool L69 3BXUK

Molecular dynamics simulations have been employed to investigate displacement cascades in Ni3Al, with energy Ep in the range from 0.15 to 10 keV. The efficiency of production of frenkel pairs declines with the increasing cascade energy in a fashion similar to that found recently for pure metals. The antisite defects are much more numerous than the frenkel pairs, and their production efficiency increases with the increasing cascade energy. A new empirical relationship between the defect number and damage energy is proposed, namely Ndefect = AEpm. A high proportion of the atomic mixing occurs in the ballistic phase and is larger for the Ni atoms, implying that the phenomenon is not purely a liquid-like process.

关键词： Ni3Al displacement cascades defect production atomic mixing molecular dynamics.

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分子-表面互作用中能量传递的激光测量

中国激光 1983年第Z1期 490-490页

作者： F.frenkel j.Hger W.Krieger H.Walther G.Ertl H.Robota j.Segner W.Vielhaber 德意志联邦共和国马-普量子光学研究所德意志联邦共和国马-普量子光学研究所德意志联邦共和国马-普量子光学研究所德意志联邦共和国马-普量子光学研究所德意志联邦共和国慕尼黑大学物理化学研究所德意志联邦共和国慕尼黑大学物理化学研究所德意志联邦共和国慕尼黑大学物理化学研究所德意志联邦共和国慕尼黑大学物理化学研究所加欣加欣加欣加欣慕尼黑慕尼黑慕尼黑慕尼黑

原子和分子束从固体表面的散射是一种用于研究气-固界面互作用动力学的重要技术。把表面散射与激光诱导荧光结合起来打开了测量表面散射分子的内部态分布和速度分布的可能性,这种测量具有高的灵敏度和优异的态分辨率。在本实验中,一束... 详细信息

原子和分子束从固体表面的散射是一种用于研究气-固界面互作用动力学的重要技术。把表面散射与激光诱导荧光结合起来打开了测量表面散射分子的内部态分布和速度分布的可能性,这种测量具有高的灵敏度和优异的态分辨率。在本实验中,一束超声速的NO分子束被一个石墨表面或一个铂（111）表面所散射,这些表面或者是洁净的或者是为NO、C和O所复盖。在不同的表面温度T8对具有两种不同动能的入射分子束,测量了散射分子的角分布。

关键词：表面散射分子束粒子束表面温度

Ni_3Al位移级联过程中缺陷的生成和原子混合

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中国科学（E辑） 1997年第5期27卷 474-480页

作者：高飞王天民 A.F.Calder D.j.Bacon 兰州大学材料科学系兰州730000 Department of Materials Scicnce and Engineering University of Liverpool Liverpool L69 3BX England

运用分子动力学方法研究Ｎｉ３Ａｌ中能量从１５０ｅＶ到１０ｋｅＶ范围的位移级联过程，发现Ｆｒｅｎｋｅｌ对的产生率随级联能的增加而减少，其趋势与最近在纯金属中得到的结果相似；反位缺陷的数目远大于Ｆｒｅｎｋｅｌ对，其产生率... 详细信息

运用分子动力学方法研究Ｎｉ３Ａｌ中能量从１５０ｅＶ到１０ｋｅＶ范围的位移级联过程，发现Ｆｒｅｎｋｅｌ对的产生率随级联能的增加而减少，其趋势与最近在纯金属中得到的结果相似；反位缺陷的数目远大于Ｆｒｅｎｋｅｌ对，其产生率随级联能的增加而增加。

关键词：位移级联缺陷产生率原子混合金属合金

Interatomic Potentials for Some Binary Oxides

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journal of Materials Science & Technology 2001年第6期17卷 638-642页

作者： M.Nadeem, M.j.Akhtar, R.Shaheen and M.N.Haque Nuclear Physics Division, Pakistan Institute of Nuclear Science and Technology, P.O. Nilore, Islamabad, Pakistan A.Y.Khan Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan Inst Nucl Sci & Technol Div Nucl Phys Islamabad Pakistan

Using atomistic computer simulation methods we have derived a new set of interatomic potential parameters for some binary oxides, comprising divalent transition elements (rock-salt structured) and tetravalent metals. Computational techniques based on the minimization of the crystal energy with respect to atomic coordinates have been employed. Crystal properties were calculated and compared with the experimental data to check the reliability of our potential models. Intrinsic (Schottky and frenkel) defect energies were also calculated and compared with previous studies. There is a good agreement between these calculations, which shows that the new potential parameters are reliable and can be used with confidence for future investigations.

关键词： constants frenkel derivation coordinates struc divalent Faraday ionic fitting dipole