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Assessing conservation practices in Amalacaxco Gorge (Izta-Popo National Park, Central mexico) using fallout 137Cs and Optically Stimulated Luminescence (OSL)

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Journal of mountain Science 2018年第3期15卷 447-460页

作者： mUNOZ-SALINAS E CASTILLO m Departamento de Geología Regional Universidad Nacional Autónoma de México Ciudad UniversitariaCiudad de MexicoMexico Laboratorio Nacional de Geoquimicay mineralogia Ciudad Universitaria Ciudad de Mexico Mexico

This study aims to assess conservation practices in Izta-Popo National Park(Central mexico) by evaluating the mechanisms of sediment transfer. We applied a methodology based on fallout ^(137)Cs and optically stimulated luminescence(OSL) analysis. This was tested in the upper catchment of Amalacaxco Gorge, selected for being one of the sectors of the park in which man-made actions have been implemented in last decades to favor forest growth in the alpine grassland and to reduce the effect of water runoff. We quantified the ^(137)Cs activity using gamma and beta spectrometry of fine sediment grains extracted from the surface of parcels of 0.4 m2 in areas of natural forest, natural alpine grassland, alpine grassland with conservation practices, ravines and trails. In general, ^(137)Cs values increases as local slope decreases as it was expected. The natural forest is the most stable area in terms of soil erosion and sediment accumulation and, mean ^(137)Cs activity was taken as reference to assess cumulative zones, with higher ^(137)Cs values and erosive, with lower. We found that trails are accumulative surfaces but in other areas, erosion predominates. man-made ditches, trenches and afforestation in the alpine grassland have higher ^(137)Cs values than thenatural grassland, which indicates that conservation practices are limiting the sediment transfer from hillslopes to channels, however, soil retention is less than in the natural grassland. Additionally, we evaluated the luminescence(OSL) values obtained from samples extracted from the sediment transported in ravines that are cutting into different sectors of the study area to assess the grade of resetting of fluvial materials. These luminescence results indicated that the sediment transported in ravines that are cutting into the natural forest and alpine grassland is bleached more efficiently than the sediment transported in the alpine grassland with conservation practices. Results of fallout ^(137)Cs and luminesce

关键词：国家公园放射性墨西哥惯例保存估计尘埃中央

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Ready to migrate?Reading cellular signs of migration in an epithelial to mesenchymal transition model

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BIOCELL 2022年第11期46卷 2353-2356页

作者： TAmARA FERNÁNDEZ-CALERO IGNACIO LÓPEZ mARCOS DAVYT CORA CHALAR RICARDO EHRLICH mÓNICA mARÍN Biochemistry-molecular Biology Faculty of ScienceUniversidad de la RepúblicaMontevideo11400Uruguay Bioinformatics Unit Institut Pasteur de MontevideoMontevideo11400Uruguay Departamento de Ciencias Exactas y Naturales Universidad Católica del UruguayMontevideo11600Uruguay Institut Pasteur de montevideo Montevideo11400Uruguay

The epithelial to mesenchymal transition(EmT)is a cellular program that drives de-differentiation of cells in both physiological and pathological *** of the characteristics of cells describing an EmT is the(re)acquisition of a motility capacity that allows them to migrate through the original tissue as well as to other sites in the *** molecular mechanisms that control the EmT are rapidly emerging and here we add to the idea that the adaptation required for cells to commit to the EmT includes adjustments of the translation machinery and metabolic pathways to cope with a high demand of extracellular components.

关键词： EmT migration Translation machinery metabolism

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Experimental investigation on the deformation characteristics of locking-steel-pipe(LSP)pile retaining structure during excavation in sand

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Underground Space 2022年第6期7卷 1098-1114页

作者： Shi Wei Rongzhu Liang Guoxiong mei m.Hesham El Naggar Lianwei Sun Jinqing Jia Xiaohua Bao Xiaojian Wu Wenbing Wu Faculty of Engineering China University of GeosciencesWuhanHubei 430074China Guangxi Key Laboratory of Disaster Prevention and Engineering Safety College of Civil Engineering and ArchitectureGuangxi UniversityNanningGuangxi 530004China Geotechnical Research Centre Faculty of EngineeringThe University of Western OntarioLondonON N6A 5B9Canada Shanghai Construction Group Co. Ltd.Shanghai 200080China School of Civil Engineering Dalian University of TechnologyDalian 116024China College of Civil and Transportation Engineering Shenzhen UniversityShenzhenGuangdong 518060China

Locking-steel-pipe(LSP)piles connect with adjacent joints to form a pile row enclosure *** to the advantages of quick construction,efficiency in installation,and recycle utilization,the connected LSP piles are frequently used as retaining structure in deep ***,systematic studies of the deformation mechanism of the LSP pile retaining structure are rarely reported,and it still lack of experimental evidence to optimize the *** this study,a braced supported excavation experimental model test in sand was designed and conducted to investigate the deformation characteristics of LSP pile retaining *** dimensional(3D)printing technique was creatively applied to manufacture LSP model *** experimental results show that,a“S”shaped distribution of bending moments is observed along pile shaft when excavation is executed;the deflection of pile shaft develops deep-seated movements toward the excavation side as excavation went deeper,resulting in a“bowl”ground *** the deflection of LSP piles,a rotating trend was occurred between pairs of locking joint,and the severe open deformation of locking joint arose on excavation *** was a gradual reduction in earth pressure behind the LSP pile retaining wall with excavation *** earth pressure between two struts level had no obvious changing,owing to the supported effect of inner struts.

关键词： Locking-steel-pipe(LSP)piles Deep excavation model test Deformation characteristics Three dimensional(3D)printing

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Size-manipulation,compaction and electrical properties of barium manganite nanorods synthesized via the CHm method

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Progress in Natural Science:materials International 2013年第4期23卷 388-394页

作者： Khizar Hayat m.A.Rafiq Atta ur Rahman Abid Ali Khan m.m.Hasan materials Research Laboratory Institute of Physics and ElectronicsUniversity of PeshawarKhyber Pakhtunkhwa 25120Pakistan micro and Nano Devices Group Department of Metallurgy and Materials EngineeringPakistan Institute of Engineering and Applied SciencesP.O.NiloreIslamabad 45650Pakistan Centre of Biotechnology & microbiology University of PeshawarKhyber Pakhtunkhwa 25120Pakistan

A composite-hydroxide mediated method was employed to synthesize barium manganite ***,surface smoothness and uniformity of these nanorods were optimized by varying reaction temperature and reaction *** rods with an average diameter of 200 nm and length of1–1.5 μm were obtained at optimum conditions of 200 1C/48 *** dielectric study of these rods reveals that they have higher value of dielectric constant at lower frequencies which was attributed to the interfacial and rotational type ***,the increase in dielectric constant with temperature was attributed to the thermal activation of such ***,the analysis of ln(J) vs.E1/2characteristics in the temperature range of 300–400 K shows that possible operative conduction mechanism was of Poole–Frenkel *** value of βexp was found to be 4.85 times greater than the expected theoretical value of feld lowering coeffcient with an internal feld enhancement factor ofα2 *** high value of βexp may be due to some localized electric felds existing inside the sample.

关键词： BamnO3 nanorods Electrical properties Dielectric properties DC conduction mechanism

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A simple method of tuning series cascade controllers for unstable systems

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控制理论与应用（英文版） 2013年第4期11卷 661-667页

作者： Simi SANTOSH m.CHIDAmBARAm Department of Chemical Engineering Indian Institute of Technology Madras

A simple method is proposed to design P/PI controllers for a series cascade control system for unstable first order plus time-delay （FOPTD） systems. In this paper, the controller design for unstable FOPTD systems cascaded in series with stable/unstable FOPTD systems is considered. The proposed method is based on equating the coefficients of corresponding powers of s and s2 in the numerator to α1 and α2 times those of the denominator of the closed-loop transfer function for a servo problem. The open loop system consists of an unstable FOPTD system cascaded in series with a stable/unstable FOPTD system. Only two tuning parameters （α1 and α2） are required for the design of controllers. The closed-loop performances are evaluated for both the servo and regulatory problems and the performances are found to be better than that of the well established synthesis method. The robustness for uncertainty in the model parameters is studied and compared with that of the controllers designed by the synthesis method.

关键词： Cascade control Time-delay process PI controller P controller FOPTD model Tuning

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Environmental monitoring of Bombetoka Bay and the Betsiboka Estuary,madagascar,Using multi-temporal Satellite Data

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Journal of Earth Science 2010年第2期21卷 210-226页

作者： Tsilavo Raharimahefa Timothy m Kusky Department of Earth Sciences Laurentian University Three Gorges Research Center for Geo-hazard Ministry of EducationChina University of Geosciences(Wuhan) State Key Laboratory of Geological Processes and mineral Resources China University of Geosciences(Wuhan)

The causes and consequences of soil erosion in madagascar have been the focus of recent environmental debates. The Betsiboka, madagascar＇s largest river stretching 600 km from the high central plateau to the northwest coast on the mozambique Channel, is a major conduit for transporting lateritic soils and sediments derived from the highlands of Central madagascar to the sea. These en- trained lateritic sediments color the river a blood-red hue, as if the life of the island is being drained away. In this study, Landsat visible and near infrared spectral bands are used to map the underwater sediments especially under the sea and in the interface between seawater and freshwater. Band color composites, single bands and band ratios are used to improve the detection of underwater sediments including sand bars and delta lobes. We show the evolution of the bay, coastline, delta, and change detection results derived from Landsat satellite images recorded in 1973, 1989, 1999, 2000 and 2003, respectively. Results indicate that sedimentary transport and suspension in Bombetoka Bay has significantly changed during the past 30 years, with a dramatic increase in the amount of sediment moved by the river, and deposited in the estuary and in offshore delta lobes. These changes have adversely affected agriculture, fisheries, and transportation for one of madagascar＇s largest ports. The changes are attributed to increased erosion following large-scale deforestation, bush fires, and overgrazing in the river basin.

关键词： environment monitoring madagascar delta remote sensing Landsat.

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The geology, structure and mineralisation of the Oyu Tolgoi porphyry copper-gold-molybdenum deposits, mongolia： A review

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Geoscience Frontiers 2016年第3期7卷 375-407页

作者： T.m.(mike) Porter Porter CeoConsultancy Ply Ltd. Linden Park 5065 SA Australia

The Oyu Tolgoi cluster of seven porphyry Cu-Au-mo deposits in southern mongolia,define a narrow,linear,12 km long,almost continuously mineralised trend,which contains in excess of 42 mt of Cu and1850 t of Au,and is among the largest high grade porphyry Cu-Au deposits in the *** deposits lie within the Gurvansayhan island-arc terrane,a fault bounded segment of the broader Silurian to Carboniferous Kazakh-mongol arc,located towards the southern margin of the Central Asian Orogenic Belt,a collage of magmatic arcs that were periodically active from the late Neoproterozoic to PermoTriassic,extending from the Urals mountains to the Pacific *** at Oyu Tolgoi is associated with multiple,overlapping,intrusions of late Devonian（～372 to 370 ma） quartzmonzodiorite intruding Devonian（or older） juvenile,probably intra-oceanic arc-related,basaltic lavas and lesser volcaniclastic rocks,unconformably overlain by late Devonian（～370 ma） basaltic to dacitic pyroclastic and volcano sedimentary *** quartz-monzodiorite intrusions range from earlymineral porphyritic dykes,to larger,linear,syn-,late- and post-mineral dykes and *** was deposited within syn-mineral quartz-monzodiorites,but is dominantly hosted by augite basalts and to a lesser degree by overlying dacitic pyroclastic *** ore deposition,an allochthonous plate of older Devonian（or pre-Devonian） rocks was overthrust and a post-ore biotite granodiorite intruded at～365 *** is characterised by varying,telescoped stages of intrusion and *** A-type quartz veined dykes were followed by Cu-Au mineralisation associated with potassic alteration,mainly K-feldspar in quartz-monzodiorite and biotite-magnetite in basaltic *** reflux of cooled,late-magmatic hydrothermal fluid resulted in intense quartz-sericite retrograde alteration in the upper parts of the main syn-mineral intrusions,and an equivalent chlorite-muscovite/illite-hematite assemblage in bas

关键词： Tectonic setting Porphyry copper-gold-molybdenum deposit High sulphidation Geology Alteration Structure

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Evolution of Dissipative Anisotropic Expansion-Free Axial Fluids

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Communications in Theoretical Physics 2015年第8期64卷 139-144页

作者： m.Sharif Zunaira Nasir Department of mathematics University of the Punjab Quaid-i-Azam Campus

A general study of non-static restricted class of axial system with anisotropic dissipative expansion-free fluid under geodesic condition is carried out. It is found that expansion-free model must be dissipative under geodesic condition to preserve axial symmetry. We also investigate this system without geodesic condition. Finally, the role of dissipation is explored via transport equation.

关键词： general relativity dissipative systems analytical

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Ha Line Polarization in the 2B/X4.8 Flare of 2002 July 23

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Chinese Journal of Astronomy and Astrophysics 2003年第3期3卷 266-276页

作者： ZhiXu N.m.Firstova DepartmentofAstronomy NanjingUniversityNanjing210093 InstituteofSolar-TerrestrialPhysics RussianAcademyofSciencesSiberianDivisionRussia

On 2002 July 23, a 2B/X4.8 flare was observed in the Hα line spec-tropolarimetrically by the Large Solar Vacuum Telescope of Baikal AstrophysicalObservatory. Linear polarization of 3%-10% was detected in the Hα line, particu-larly where the line showed central reversal. The linear polarization is mainly radialon the solar disk and appears at the impulsive phase of the hard X-ray and γ-raybursts. It is limited to some relatively small regions of the flare. The polarizationin a limited small region (～ 4″ - 5″) changed its direction within a short period oftime (～ 10s).

关键词： Polarization - line: profile - Sun: flare

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Effect　of　Ballistic-Type　Hot　Atom　Adsorption　mechanism　on　the　Phase　Diagram　of　monomer　Dimer　CO-O2　Surface　Catalytic　Reaction：　A　monte　Carlo　Simulation

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Chinese Physics Letters 2004年第6期21卷 1171-1174页

作者： m.Khalid K.m.Khan A.U.Qaisrani Q.N.malik DepartmentofPhysics GomalUniversityDeraIsmailKhanPakistan NuclearPhysicsDivision PakistanInstituteofNuclearScienceandTechnology(PINSTECH)P.O.NiloreIslamabadPakistan

We investigate the effect of the ballistic mechanism on the phase diagram using a square surface. While using this mechanism whenever an O2 molecule hits a randomly vacant selected site, the molecule breaks up into atomic form and then executes a ballistic flight. The paths of the two oxygen atoms are taken exactly to be opposite to each other, ***-parallel, and the ranges of the atoms are taken to be equal, *** may fly up to 1 or 1.414 or 2 of the atomic spacing from the site of impact. Four cases have been studied on the basis of the range of hot atoms. The range of the hot oxygen atoms executing a ballistic flight might be up to the first nearest neighbourhood (1 atomic spacing from the site of impact), the second nearest neighbourhood (1.414 atomic spacing from the site of impact), the third nearest neighbourhood (2 atomic spacing from the site of impact), known as cases a, b, and c, respectively, while for case d the range of the oxygen atoms executing the ballistic flight might be up to 1 atomic spacing or 1.414 atomic spacing or 2 atomic spacing from the site of impact. The steady reactive window is observed and the continuous transition disappears. As soon as the CO partial pressure departs from zero, the production of CO2 is observed, which clearly verifies the experimental observation.

关键词： Oxygen

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