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materials Sciences and Applications 2018年第7期9卷 565-575页

作者： L. m. Flores-Vélez O. domínguez Faculty of Chemistry UASLP San Luis Potosí México Institute of metallurgy UASLP San Luis Potosí México

Graphene Oxide/multilayer-Graphene (GO-mG) flakes were obtained using an electrochemically exfoliated graphite (GR) electrode from secondary steel-making industry performed in a two-electrode system using tungsten as the counter electrode and GR as the working electrode. The exfoliated GO-mG flakes were processed and incorporated in an elastomeric polyurethane (PU) matrix. The mechanical properties of the PU/GO-mG composites were evaluated and compared with equivalent composites made of PU/GR powder. From experimental data analysis it was concluded that GO-mG flakes were approximately composed of 67 wt% GO and 33 wt% mG. The number of layers in the graphene flakes was estimated to be between 2 and 5 sheets. PU showed a breaking stress of 570 kPa, while the PU/20wt% GR attained a maximum stress of 750 kPa as compared to PU/10wt% GO-mF composite exhibiting a breaking stress of 1060 kPa.

关键词： Electrochemical Exfoliation Graphene Oxide Nanocomposites Polyurethane

The Thermal Decomposition of Ammonium Perchlorate-Aluminum Propellants in Presence of metallic Zinc Particles

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materials Sciences and Applications 2017年第6期8卷 436-447页

作者： mónica Rodríguez-Pesina Jorge García-domínguez Felipe García-Hernández Luisa maria Flores-Vélez Octavio domínguez Institute of metallurgy UASLP San Luis Potosi México INIDETAm Polígono Naval Antón Lizardo Veracruz México Faculty of Chemistry UASLP San Luis Potosi México

The thermal decomposition of ammonium perchlorate (AP) with Al and Zn metallic particles was studied at different heating rates in dry air atmosphere and the combustion behavior of AP/Al/Zn propellant was evaluated. The exothermic reaction kinetics was studied by differential thermal analysis (DTA) in non-isothermal conditions and compare with the thermal decomposition of pure AP and AP/aluminum particles analyzed in the same experimental conditions. The Arrhenius parameters were estimated according to the Ozawa and Kissinger methods. The calculated activation energies for the low and high temperature exothermic reactions were 91 and 229 kJ/mol for pure AP, 90 and 112 kJ/mol for 80 wt% AP/20 wt% Al particles. When zinc was incorporated, activation energy of 56 kJ/mol was determined for the only exothermic peak observed for 90 wt% AP/10 wt% Zn and 44 kJ/mol for 78.4 wt% AP/19.6 wt% Al/2 wt% Zn propellant composition.

关键词： Thermal Analysis Ozawa method Kissinger method Thermal Decomposition Ammonium Perchlorate Propellants

Ultrasonic Fatigue Endurance Investigation on Plastic material Nylon 6

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materials Sciences and Applications 2011年第9期2卷 1293-1297页

作者： Gonzalo m. domínguez Almaraz Erasmo Correa Gómez 不详

Ultrasonic fatigue tests were carried out on the plastic material Nylon 6. Special attention was devoted to the temperature control in order to avoid physic-chemical transformation of this low melting point material. Under ultrasonic fatigue tests, important heat dissipation takes place at the narrow section of hourglass shape specimen leading to high temperature at this zone. The specimen was calculated to meet the resonance condition with the smallest dimensions at its narrow section, with aim to reduce the temperature gradient at this zone of this non heat conducting material. Temperature at narrow section was maintained lower than 45℃ using a cooling system with cooling air;under this condi- tion the ultrasonic fatigue tests were performed. Experimental tests were carried out at low loading range (9 - 12.5% of the elastic limit of material) in order to control the highest temperature and to avoid that specimen was out of resonance condition. Experimental results are analyzed together with the fracture surfaces and conclusions are presented concerning the ultrasonic fatigue endurance of this polymeric material.

关键词： Ultrasonic Fatigue Tests Polymeric material Numerical Simulation Temperature Control Fatigue Life Fracture Surface

Petrology of ultramafic to mafic cumulate rocks from the G?ksun(Kahramanmaras) ophiolite,southeast Turkey

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Geoscience Frontiers 2020年第1期11卷 109-128页

作者： Osman Parlak Utku Bagcı Tamer Rızaoglu Corina Ionescu GüzideÖnal Volker Höck Hüseyin Kozlu Çukurova Universitesi Jeoloji Mühendisligi BölümüBalcalıTR-01330 AdanaTurkey State Key Laboratory of Geological Processes and mineral Resources Center for Global TectonicsSchool of Earth SciencesChina University of GeosciencesWuhan 430074China mersin Universitesi Jeoloji Mühendisligi BölümüÇiftlikköyTR-33343 MersinTurkey Kahramanmaras¸SütçüImam Universitesi Jeoloji Mühendisligi BölümüAvs¸ar KampüsüTR-46100 KahramanmarasTurkey Babes-Bolyai University Geology Department1 Kogalniceanu Str.RO-400084 Cluj-NapocaRomania Kazan(Volga Region)Federal University Archeotechnologies&Archeological Material Sciences Laboratory18 Kremlevskaya Str.420000 KazanRussia University of Salzburg Division of Geography and Geology34 Hellbrunner Str.A-5020 SalzburgAustria Türkiye Petrolleri Anonim Ortaklıgı TR-06520 AnkaraTurkey

The G?ksun(Kahramanmaras)ophiolite(GKO),cropping out in a tectonic window bounded by the malatya metamorphic unit on both the north and south,is located in the EW-trending lower nappe zone of the southeast Anatolian orogenic belt(Turkey).It exhibits a complete oceanic lithospheric section and overlies the middle Eocene maden Group/Complex with a tectonic contact at its *** ophiolitic rocks and the tectonically overlying malatya metamorphic(continental)unit were intruded by I-type calc-alkaline Late Cretaceous granitoid(~81-84 ma).The ultramafic to cumulates in the GKO are represented by wehrlite,plagioclase wehrlite,olivine gabbro and *** crystallization order for the cumulate rocks is as follows:olivine±chromian spinel→clinopyroxene→*** major and trace element geochemistry as well as the mineral chemistry of the ultramafic to mafic cumulate rocks suggest that the primary magma generating the GKO is compositionally similar to that observed in the modern island-arc tholeiitic *** mineral chemistry of the ultramafic to mafic cumulates indicates that they were derived from a mantle source that was previously depleted by earlier partial melting *** highly magnesian olivine(Fo77-83),clinopyroxene(mg#of 82-90)and the highly Ca-plagioclase(An81-89)exhibit a close similarity to those,which formed in a supra-subduction zone(SSZ)*** field and the geochemical evidence suggest that the GKO formed as part of a much larger sheet of oceanic lithosphere,which accreted to the base of the Tauride active continental margin,including the ispendere,K?mürhan and the Guleman *** latter were contemporaneous and genetically/tectonically related within the same SSZ setting during the closure of the Neotethyan oceanic basin(Berit Ocean)between the Taurides to the north and the Bitlis-Pütürge massif to the south during the Late Cretaceous.

关键词： Göksun(Kahramanmaras)ophiolite Cumulate SSZ-Spreading Neotethys Late Cretaceous SE Anatolia

Benzyl Amino Purine and Gibberellic Acid Coupled to Nitrogen-Limited Stress Induce Fatty Acids,Biomass Accumulation,and Gene Expression in Scenedesmus Obliquus

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Phyton-International Journal of Experimental Botany 2021年第2期90卷 515-531页

作者： Hans Christian Correa-Aguado Gloria Viviana Cerrillo-Rojas Alejandro Rocha-Uribe Ruth Elena Soria-Guerra JoséFrancisco morales-domínguez Departamento de Química Centro de Ciencias BásicasUniversidad Autónoma de AguascalientesAguascalientes20131México Facultad de Ciencias Químicas Universidad Autónoma de San Luis PotosíSan Luis Potosí78210México Instituto Politécnico Nacional Unidad Profesional Interdisciplinaria de Ingeniería Campus ZacatecasBlvd.del Bote 202Cerro del Gato Ejido La EscondidaCol.Ciudad AdministrativaZacatecasZAC 98160Mexico

The need for renewable energy sources makes microalgae an essential feedstock for biofuels *** molecular aspects and the response to nitrogen(N)-limited conditions with a phytohormone stimulus in microalgae have been slightly *** this work,Scenedesmus obliquus was used as a study model to analyze the effect of benzyl amino purine(BAP)and gibberellic acid(GA)coupled to nitrogen limitation on cell growth,biomass and fatty *** selected 10^(-5)m BAP increased the biomass by 1.44-fold,and 10^(-6)m GA by *** total lipids also increased by 2.8 and 1.11-fold,*** 10^(-5)m BAP and 10^(-6)m GA addition to *** cultures at different initial nitrogen percentages(N-0,N-25,and N-50)showed a significant increase in cell growth and biomass productivity compared to the unstimulated *** N-0 and GA N-0 produced the highest lipid yields with 55%and 50%,*** lipid profile analysis revealed an increase,particularly in C18:1 and C16:0 fatty *** expression analysis showed an over-expression of acyl carrying protein(ACP),stearoyl-ACP desaturase(SAD),fatty acid acyl-ACP thioesterase(FATA),and diacylglycerol acyltransferase(DGAT)genes,which were mainly induced by nitrogen ***,BAP and GA produced a significant over-expression on these genes in the N-replete *** study shows that BAP and GA,coupled to N limitation stress,can be used to increase the biomass and lipid production in *** for sustainable biofuels.

关键词： Biodiesel gene expression lipids microalgae nitrogen deficiency phytohormones

In Vitro Propagation of Agave guiengola Gentry Using Semisolid medium and Temporary Immersion Bioreactors

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Phyton-International Journal of Experimental Botany 2021年第3期90卷 1003-1013页

作者： Lucía Isabel Chávez-Ortiz JoséFrancisco morales-domínguez Araceli Rodríguez-Sahagún Eugenio Pérez-molphe-Balch Departamento de Química Centro de Ciencias BásicasUniversidad Autónoma de AguascalientesAguascalientes20131México Laboratorio de Biología molecular Vegetal Centro Universitario de la CiénegaUniversidad de GuadalajaraOcotlán47820México

Agave guiengola Gentry is an endemic plant from a very small locality in Oaxaca,*** conservation status is fragile and can rapidly *** of its scarcity,this agave has been used solely for ornamental purposes,but it could have other uses if more plants were *** vitro propagation by enhanced axillary sprouting from stem segments was attained using murashige and Skoog Basal medium(mS)as well as basal medium supplemented with cytokinins 6-Benzylaminopurine(BA)or 6-(γ,γ-Dimethylallylamino)purine(2iP).The best treatment for shoot induction in semisolid medium consisted in mS supplemented with 2 mg l^(–1) BA,obtaining a mean of 3.7 shoots per *** interesting responses were observed,such as nodular callus induction using combinations of BA and 2,4-Dichlorophenoxyacetic acid(2,4-D);root induction without Plant Growth Regulators(PGR);and generation of shoot *** clusters constituted an excellent explant for micropropagation in temporary immersion bioreactors,obtaining a propagation rate of 43 shoots per explant with 1 min immersion and 6 h immersion *** new plants rooted and survived the transfer to *** study developed an in vitro propagation scheme to produce individuals that can be used either for reforestation,economical purposes,or to carry out studies in this species to assess its full potential,avoiding exploitation from wild plants.

关键词： Agavaceae temporary immersion systems callus induction micropropagation

Classification and management of bile duct injuries

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World Journal of Gastrointestinal Surgery 2011年第4期3卷 43-48页

作者： miguel Angel mercado Ismael domínguez Department of Surgery Instituto Nacional de Ciencias Médicasy Nutrición "Salvador Zubirán"P.C.14000 MéxicoDFMexico

To review the classification and general guidelines for treatment of bile duct injury patients and their long term results. In a 20-year period, 510 complex circumferential injuries have been referred to our team for repair at the Instituto Nacional de Ciencias médicasy Nutrición "Salvador Zubirán" hospital in mexico City and 198 elsewhere (private practice). The records at the third level Academic University Hospital were analyzed and divided into three periods of time: GⅠ-1990-99 (33 cases), G Ⅱ2000-2004 (139 cases) and GⅢ2004-2008 (140 cases). All patients were treated with a Roux en Y hepatojejunostomy. A decrease in using transanastomotic stents was observed (78% vs 2%, P = 0.0001). Partial segment Ⅳ and Ⅴ resection was more frequently carried out (45% vs 75%, P = 0.2) (to obtain a high bilioenteric anastomosis). Operative mortality (3% vs 0.7%, P = 0.09), postoperative cholangitis (54% vs 13%, P = 0.0001), anastomosis strictures (30% vs 5%, P = 0.0001), short and long term complications and need for reoperation (surgical or radiological) (45% vs 11%, P = 0.0001) were significantly less in the last period. The authors concluded that transition to a high volume center has improved long term results for bile duct injury repair. Even interested and tertiary care centers have a learning curve.

关键词： Bile duct injury Hepatojejunoanastomosis Biliary repair Hepatectomy Cholangitis

Situation of China's solar water heater industry,related national standards,testing and the Golden Sun certification program

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Journal of Chongqing University 2008年第2期7卷 107-112页

作者：严军 H.Drück H.müller-Steinhagen Department of mechanical Engineering Qinghai University Institute of Thermodynamics and Thermal Engineering University of StuttgartStuttgart 70550Germany

China is the largest solar water heater producer and market in the *** the fast growth and an installed capacity that accounts for the majority of the global gross,China's per capita solar hot water capacity is still very low,implying a huge margin of market potential;and the recognition of the industry in the global market is handicapped by the scattered scale of production and inconsistent product *** ensure continued growth of China's solar water heating(SWH) industry,Chinese Government has established a series of national SWH standards,three national testing centers,and a certification program to lay the foundation for the development of the Golden Sun product labeling *** General Certification Center(CGC) developed the Golden Sun product certification and labeling system on a pass/fail basis evaluating with established *** system was designed to help manufacturers acclimate to explicit consistent requirements and to identify and fix the deficiencies in the design and execution of the program *** revision and integration of the national standards are recommended to accommodate the test procedures and requirements to new technologies and the evolving SWH *** implementation of the Golden Sun certification and labeling system are suggested to avail improving the quality control and forging internationally reputable brands of Chinese solar water heating products.

关键词： solar water heaters solar heating renewable energy resources national standards Golden Sun certification program

Emission spectroscopy of NaYF_(4):Eu nanorods optically trapped by Fresnel lens fibers

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Photonics Research 2022年第2期10卷 332-339页

作者： Aashutosh Kumar Asa Asadollahbaik Jeongmo Kim Khalid Lahlil Simon Thiele Alois m.Herkommer Síle nic Chormaic Jongwook Kim Thierry Gacoin Harald Giessen Jochen Flck Universite Grenoble Alpes CNRSInstitut Neel38000 GrenobleFrance 4th Physics Institute and Research Center SCoPE University of Stuttgart70569 StuttgartGermany Universite Paris Saclay CNRSLaboratoire de Physique de la Matiere CondenseeEcole Polytechnique91128 PalaiseauFrance Institute of Applied Optics and Research Center SCoPE University of Stuttgart70569 StuttgartGermany Okinawa Institute of Science and Technology Graduate University Okinawa 904-0495Japan

NaYF_(4):Eu nanorods with high aspect ratios are elaborated and optically trapped using dual fiber optical tweezers in a counterpropagating geometry. High trapping efficiency is observed using converging beams, emitted from diffractive Fresnel lenses directly 3D printed onto cleaved fiber facets. Stable nanorod trapping and alignment are reported for a fiber-to-fiber distance of 200 μm and light powers down to 10 m W. Trapping of nanorod clusters containing one to three nanorods and the coupling of nanorod motion in both axial and transverse directions are considered and discussed. The europium emission is studied by polarization-resolved spectroscopy with particular emphasis on the magnetic and electric dipole transitions. The respective σ and π orientations of the different emission lines are determined. The angles with respect to the nanorod axes of the corresponding magnetic and electric dipoles are calculated. mono-exponential emission decay with decay time of 4–5 ms is reported. It is shown that the nanorod orientation can be determined by purely spectroscopic means.

关键词： nanorods Fresnel trapping

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防渗膜集成永久性渗漏监控系统的定位

环境工程学报 2017年第5期11卷 3320-3326页

作者：刘宁 GEUTEBRück Ernst RAmSEY Boyd 上海交通大学船舶海洋与建筑工程学院上海200240 Texplor GmbH Potsdam 14478 GSE Environmental Houston 77073

介绍了由导电HDPE防渗膜和预埋渗漏监控模块共同构成的集成永久性防渗膜渗漏监控系统及其基本工作原理,阐述了第3代导电防渗膜以及渗漏监控模块的特点,重点介绍了在贵州省环境保护厅监督下进行的我国第1次防渗膜永久监控系统现场验证实... 详细信息

介绍了由导电HDPE防渗膜和预埋渗漏监控模块共同构成的集成永久性防渗膜渗漏监控系统及其基本工作原理,阐述了第3代导电防渗膜以及渗漏监控模块的特点,重点介绍了在贵州省环境保护厅监督下进行的我国第1次防渗膜永久监控系统现场验证实验,就实验场地规划、导电防渗膜的安装与检测、渗漏监控模块的安装、系统调试和实验过程分别做了说明。实验结果表明,监控系统可以对直径1 cm的小孔渗漏发出实时报警信号,定位的漏点与实际漏点间的差距仅为0.68 m,相对于1 405 m^2的实验区域,定位精度达到了1/1 000,显示了极高的敏感度和良好的渗漏定位能力。该现场验证实验的成功,对于建立有效的填埋场环境监控系统有着积极的影响。

关键词：防渗膜渗漏监控渗漏定位验证实验