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窄禁带半导体的自由载流子吸收

红外与毫米波学报 1991年第4期10卷 241-245页

作者： A.E.BELYAEv N.v.SHEvCHENKO z.A.DEMIDENKO Institute of Semiconductors Academy of Sciences of the Ukrainian SSRInstitute of Semiconductors Academy of Sciences of the Ukrainian SSRInstitute of Physics Academy of Sciences of the Ukranian SSR Prospect Nauki 45 Kiev-28 252650 USSRProspect Nauki 45 Kiev-28 252650 USSRProspect Nauki 46 Kiev-28 252028 USSR

从理论和实验上研究了77K和300K温度下,本征型半导体InSb,Hg_(1-x)Cd_xTe,Hg_(1-x)Mn_xTe和高掺杂Hg_(1-x)Cd_xTe在2.5～50μm波段范围内的自由载流子吸收,结果表明:对于所研究的三种本征型样品,均是极性光学声子散射起主要作用,对于InS... 详细信息

从理论和实验上研究了77K和300K温度下,本征型半导体InSb,Hg_(1-x)Cd_xTe,Hg_(1-x)Mn_xTe和高掺杂Hg_(1-x)Cd_xTe在2.5～50μm波段范围内的自由载流子吸收,结果表明:对于所研究的三种本征型样品,均是极性光学声子散射起主要作用,对于InSb还应考虑声学声子和电离杂质散射。对有缺陷的Hg_(1-x)Mn_xTe样品,理论计算的自由载流子吸收系数与实验值不一致,表明存在附加的散射机制,对高掺杂Hg_(1-x)Cd_xTe的研究证实了这一假设。还讨论了非弹性电子-声子散射机制的起因,估算了特性参数。

关键词：窄禁带半导体自由载流子

Optical studies of Y3（Al,Ga）5O12:Ce3+,Cr3+,Nd3+ nano-phosphors obtained by the Pechini method

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Journal of Rare Earths 2019年第11期37卷 1132-1136页

作者： z.Dai v.Boiko M.Markowska A.Gerus K.Grzeszkiewicz J.Holsa M.L.Saladino D.Hreniak Institute of Low Temperature and Structure Research Polish Academy of SciencesOkolna 2.PL-50-422 WroctawPoland Department of Physics University of the Free StateBloemfontein ZA-9300South Africa Department of Biological Chemical and Pharmaceutical Sciences and Technologies(STEBICEF)University of PalermoViale delle ScienzeBld.171-90128 PalermoItaly

The Y3(AI,Ga)5O12:Ce^3+,Cr^3+,Nd^3+(YAGG)nano-phosphors with homogeneous particle-size distribution,low aggregation and average crystalline size of about 65 nm were obtained using a modified Pechini *** slight aggregation of the crystallites occurs after post-annealing at 1100℃.The intense Ce^3+bands in the excitation spectra of the Ce^3+,Cr^3+,Nd^3+co-doped materials monitoring the Cr^3+emission at 690 nm indicate energy transfer from Ce^3+to Cr^3+.Weak Nd^3+lines are observed,as *** addition,the emission of Nd^3+at 1060 nm with excitation of Ce^3+and Cr^3+confirms the Ce^3+/Cr^3+to Nd^3+energy *** short average luminescence decay times for the Ce^3+emission indicate the Ce^3+/Cr^3+to Nd^3+energy ***,the Y3(AI,Ga)5O12:Ce^3+,Cr^3+,Nd^3+nano-phosphors exhibit persistent luminescence originating from the 4f^3→4f^3 transitions of Nd^3+which matches well to the first biological window to be used in bioimaging applications.

关键词： Nano-phosphors Ce^3+ NIR persistent luminescence Thermoluminescence Rare earths

Effects of Plant Extracts and Beauveria bassiana on the Activity of Defense-Related Enzymes in Solanum lycopersicum *** Interaction with Fusarium oxysporum ***

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Phyton-International Journal of Experimental Botany 2023年第9期92卷 2503-2518页

作者： JoséAdrian Perez-Robles Carlos Alberto Lecona-Guzmán víctor Manuel Ruíz-valdiviezo Joaquín Adolfo Montes-Molina Laboratorio de Biotecnología vegetal Tecnológico Nacional de MexicoCampus Tuxtla GutiérrezTuxtla Gutiérrez29050Mexico

The objective to this work was to evaluate the enzymatic activity in the culture of Solanum lycopersicum *** with Fusarium oxysporum after the combined application of Beauveria bassiana and plant *** lycopersicum plantlets were transplanted 15 days after the *** days after transplanting,Beauveria bassiana spores were applied at a concentration of 1×10^(7)spores mL^(−1)onto soil(along with ***(N)and ***(H)leaf extracts)where *** plants were *** days after transplanting,spores of *** strain were applied at a concentration of 1×10^(6)spores mL^(−1)to soil where *** plants were *** development of *** plants was monitored for 114 days,whereby a randomized complete block treatment design was used,the roots of the plants were crushed with liquid nitrogen,after which Uv/vIS spectrophotometry was used to determine protein concentration,as well as the activity ofβ-1,3-glucanases,peroxidases(POX,EC1.***.1.7),catalase and *** treatments combining *** and *** and *** extracts,had a significant difference in enzymatic activity levels,thus contributing to better defense mechanisms and a greater protection to *** plants in the presence of *** application of *** and plant extracts to the ground mitigated damage caused by *** on *** plants.

关键词： Glucanases chitinases peroxidases catalase defense mechanisms

Effect of multiaxial deformation on structure, mechanical properties, and corrosion resistance of a Mg-Ca alloy

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Journal of Magnesium and Alloys 2022年第1期10卷 284-298页

作者： N.Yu.Yurchenko N.D.Stepanov G.A.Salishchev v.N.Serebryany N.S.Martynenko E.A.Lukyanova L.L.Rokhlin N.Birbilis S.v.Dobatkin Y.z.Estrin Belgorod State National Research University BelgorodRussia Federal State Budget Institution of Science A.A.Baikov Institute of Metallurgy and Materials Science.Russian Academy of SciencesMoscowRussia National University of Science and Technology"MISiS" MoscoicRussia Department of Materials Engineering Monash UniversityClaytonVIC 3800Australia Department of Mechanical Engineering The University of Western AustraliaMedian ds WA 6009、Australia

This article provides a report on the effect of multiaxial deformation(MAD) on the structure, texture, mechanical characteristics, and corrosion resistance of the Mg-0.8(wt.)% Ca alloy. MAD was carried out on the alloy in the as-cast and the annealed states in multiple passes, with a stepwise decrease in the deformation temperature from 450 to 250 ℃ in 50 ℃ steps. The cumulative true strain at the end of the process was 22.5. In the case of the as-cast alloy, this resulted in a refined microstructure characterized by an average grain size of 2.7 μm and a fraction of high-angle boundaries(HABs) of 57.6%. The corresponding values for the annealed alloy were 2.1 μm and 68.2%. The predominant mechanism of structure formation was associated with discontinuous and continuous dynamic recrystallization acting in concert. MAD was also shown to lead to the formation of a rather sharp prismatic texture in the as-cast alloy, whilst in the case of the annealed one the texture was weakened. A displacement of the basal poles {00.4} from the periphery to the center of a pole figure was observed. These changes in the microstructure and texture gave rise to a significant improvement of the mechanical characteristics of the alloy. This included an increase of the ultimate tensile strength reaching 308 MPa for annealed material and 264 MPa for the as-cast one in conjunction with a twofold increase in ductility. A further important result of the MAD processing was a reduction of the rate of electrochemical corrosion, as indicated by a significant decrease in the corrosion current density in both microstructural states of the alloy studied.

关键词： Metals and alloys Multiaxial deformation Microstructure Recrystallization Mechanical properties Corrosion

Primary dendrite growth kinetics and rapid solidification mechanism of highly undercooled Ti-Al alloys

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Journal of Materials Science & Technology 2020年第5期40卷 47-53页

作者： z.C.Luo H.P.Wang Department of Applied Physics Northwestern Polytechnical UniversityXi’an 710072China

The rapid solidification processes of undercooled Ti-(47,50,54)at.%Al alloys were investigated by electromagnetic levitation(EML)method combined with a high-speed photoelectric *** maximum undercoolings of the three liquid alloys were 376 K,352 K and 316 K,*** processes corresponding to the primary dendrite growth and subsequent phase transition were recorded at various *** primary dendrite growth velocity v meets a double exponential relationship with the undercooling ***,a novel formula with physical meaning is proposed to explain that the more ordered liquid metal atoms accelerate the primary dendrite *** recalescences are found at all undercoolings for Ti-47 at.%Al alloy and at high undercoolings for Ti-50 at.%Al *** microstructures of solidified Ti-47 at.%Al alloys successively appear as coarse lamellar dendrites and finally evolve to refined parallel lamellar dendrites with the increasing *** T rises,the microstructures of solidified Ti-50 at.%Al alloys appear from coarse primary dendrites and interdendritic dendrites to refined lamellar *** the process from low undercooling to high undercooling,the primary phase of undercooled Ti-54 at.%Al alloys changes from r-Ti(r)to r-TiAl(r)and the microstructures of solidified alloys evolve from spherical primary dendrites and matrix phases to cellular dendrite ***,for the Ti-(47,50)at.%Al,the transformation temperature of metastable intermediateγphase decreases with the increase of ***,the microhardness of the three solidified alloys reaches the maximum when the undercoolings are 185 K,270 K and 316 K,respectively.

关键词： Electromagnetic levitation Rapid solidification Dendrite growth Microstructure Microhardness

Physics and applications with laser-induced relativistic shock waves

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High Power Laser Science and Engineering 2016年第3期4卷 46-59页

作者： S.Eliezer J.M.Martinez-val z.Henis N.Nissim S.v.Pinhasi A.Ravid M.Werdiger E.Raicher Institute of Nuclear Fusion Polytechnic University of Madrid Applied Physics Division Soreq NRC 42 Beery

The laser-induced relativistic shock waves are described. The shock waves can be created directly by a high irradiance laser or indirectly by a laser acceleration of a foil that collides with a second static foil. A special case of interest is the creation of laser-induced fusion where the created alpha particles create a detonation wave. A novel application is suggested with the shock wave or the detonation wave to ignite a pre-compressed target. In particular, the deuterium–tritium fusion is considered. It is suggested that the collision of two laser accelerated foils might serve as a novel relativistic accelerator for bulk material collisions.

关键词： fast ignition laser piston model relativistic shock waves ultra-intense lasers

Malignant schwannoma of the pancreas involving transversal colon treated with en-bloc resection

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World Journal of Gastroenterology 2010年第1期16卷 119-122页

作者： Miroslav P Stojanovic Milan Radojkovic Ljiljana M Jeremic Aleksandar v.zlatic Goran z Stanojevic Milan A Jovanovic Milos S Kostov vuka P Katic Department of Hepato-bilio-pancreatic Surgical ClinicClinical Center Nis

Pancreatic schwannoma is a very uncommon tumor of the pancreas,with only 27 cases *** pancreatic schwannomas are benign,with only four malignant tumors *** describe a case of giant malignant schwannoma of the pancreatic body and tail,which involved the transverse *** tumor was treated successfully with en bloc distal splenopancreatectomy and colon *** is believed to be the first reported radical operation for malignant schwannoma of the pancreatic body,with infiltration of the transverse colon,with excellent longterm *** patient is alive and well 28 mo after the *** authors conclude that pancreatic schwannomas should be considered in the differential diagnosis of cystic neoplasms of the pancreas,although the diagnosis can only be confirmed by microscopic *** the case of the benign tumors,local excision is adequate,but in the case of malignant schwannoma,oncological standards must be fulfilled.

关键词： Pancreatic neoplasms Schwannoma Colonic neoplasms Surgery

RESEARCH ON LASER DIRECT DEPOSITION PROCESS OF Ti-6Al-4v ALLOY

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Acta Metallurgica Sinica(English Letters) 2007年第3期20卷 171-180页

作者： S.Y. Gao Y.z. zhang L.K. Shi B.L. Du M.z. Xi H.z. Ji Mechanical Engineering College Yanshan University O~mhuangdao 066004 China Beijing General Research Institute for Nonferrous Metals Beijing 100088 China

Laser direct deposition （LDD） of metallic components is an advanced technology of combining CAD/CAM （computer aided design/computer aided manufacturing）, high power laser, and rapid prototyping. This technology uses laser beam to melt the powders fed coaxiaUy into the molten pool by the laser beam to fabricate fuUy dense metallic components. The present article mainly studies the LDD of Ti-6Al-4v alloy, which can be used to fabricate aircraft components. The mechanical properties of the Ti-6Al-4v alloy, fabricated by LDD, are obtained using the tension test, and the oxygen content of used powders and deposited specimens are measured. In the present article, it can be seen that the mechanical properties obtained using this method are higher than the ones obtained by casting, and equal to those got by wrought anneal. One aircraft part has been made using the LDD process. Because of this aircraft part, with sophisticated shape, the effect of the laser scanning track on the internal soundness of the deposited part was discussed.

关键词： laser direct deposition Ti-6Al-4v alloy mechanical property depositing process aircraft component

A non-renormalizable B-L model with Q_(4)×z_(4)×z_(2) flavor symmetry for cobimaximal neutrino mixing

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Chinese Physics C 2021年第12期45卷 22-35页

作者： v.v.vien Theoretical Particle Physics and Cosmology Research Group Advanced Institute of Materials ScienceTon Due Thang UniversityHo Chi Minh CityVietnam Faculty of Applied Sciences Ton Due Thang UniversityHo Chi Minh CityVietnam

We construct a non-renormalizable gauge B-L model based on Q_(4)×z_(4)×z_(2) symmetry that successfully explains the cobimaximal lepton mixing *** active neutrino masses and both neutrino mass hierarchies are produced via the type-I seesaw mechanism at the *** model is predictive;hence,it reproduces the cobimaximal lepton mixing scheme,and the reactor neutrino mixing angle θ_(13) and the solar neutrino mixing angle θ_(12) can obtain best-fit values from recent experimental *** model also predicts the effective neut-rino mass parameters of mβ∈(8.80,9.05)mev and〈m_(ee)〉∈(3.65,3.95)mev for normal ordering(NO)and mβ ∈(49.16,49.2 l)mev and(mce)∈(48.59,48.67)mev for inverted ordering(IO),which are highly consistent with recent experimental constraints.

关键词： extensions of the electroweak Higgs sector neutrino mass and mixing nonstandard-model neutrinos right-handed neutrinos discrete symmetries