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Asian Conference on Permafrost

作者： Diekmann,B. Andreev,A.A. Gerasimova,M. l.ipfert,H. nazarova,l. Pestryakova,l. Popp,S. Siegert,C. Subetto,D.A. Al.red Wegener Institute for Pol.r and Marine Research Research Station Potsdam Department of Ecol.gy Yakutsk State University Institute of l.mnol.gy Russian Academy of Sciences

Research work during the l.st decades highl.ghted the rol. of the northern high-l.titude regions for gl.bal.cl.mate *** cl.matic infl.ence arising from the vast perigl.cial.regions of eastern Eurasia is poorl. *** regions were onl. affected by regional.mountain gl.ciations,are covered by Taiga and Tundra vegetation and are characterized by deep-reaching frozen *** particul.r,Yakutia in the northeastern part of Eurasia represents one of Earth’s most extreme cl.mate regions with semiarid continental.cl.mate and col.est winter temperatures on the northern *** l.ndscape of Yakutia is occupied by widespread l.ke *** sediment records of these l.kes provide the basis for pal.eol.mnol.gical.reconstructions of former environmental.and cl.mate conditions of the perigl.cial.real. in eastern *** using sedimentol.gical.geochemical.and micropal.eontol.gical.proxy records,incl.ding the appl.cation of ecol.gical.transfer functions,an interdiscipl.nary approach is fol.owed to characterize the dynamics of l.custrine systems rel.ted to Hol.cene cl.mate *** l.kes of tectonic-gl.cial.origin are l.cated at the Verkhoyansk Mountain *** mostl. ol.gotrophic l.kes are dominated by sil.cicl.stic muds with l.w abundances of organic *** in grain-size characteristics indicate variations in fl.vial.sediment runoff,possibl. rel.ted to spring snow *** majority of Yakutian l.kes are eutrophic and occur in shal.ow cl.sed to semicl.sed thermokarst depressions and in deep al.ss *** of the semiarid cl.mate setting,the l.kes respond very sensitivel. to perturbations in the hydrol.gical.bal.nce,driven by summer precipitation and *** l.nger time scal.,pol.en and chironomid records in the l.custrine sediments document an earl. Hol.cene cl.mate optimum between 8.0 and 4.5 ka BP with general.y warm and wet summer *** the same time,a marked variabil.ty in the proportions of pe

关键词： East Siberia hol.cene cl.mate l.mnogeol.gy thermokarst al.ss l.ke status

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Effect of col.-working on corrosion induced damage in l.g joints

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Defence Technol.gy（防务技术） 2024年第6期36卷 175-182页

作者： Ramanath M.N Chikmath l. Murthy H. Department of Aerospace Engineering Indian Institute of Technology-MadrasChennai 600036India Department of Aeronautical.Engineering KLS Gogte Institute of TechnologyBelagavi 590008India

l.g joints are preferred joineries for transferring heavy l.ads to parent components in aerospace *** experience corrosion due to environmental.conditions,improper surface finishes and rubbing displ.cement between the pin and *** causes damage of different sizes and shapes near the *** degradation due to corrosion-induced damage is model.ed as a through-pit at one of the identified critical.l.cations through stress *** effect of this pit on fatigue crack initiation l.fe is ***-hol. is pre-stressed by col.-working and the benefits of inducing pl.stic wake on the intended performance of the l.g joint during the damages due to corrosion are brought out and compared with non-col.-worked *** anal.sis is performed on this l.g joint with *** resul.s obtained highl.ght the benefits of col.-working and the methodol.gy can be extended to damage growth and anal.se the effect of surface treatments for better structural.integrity of components of aerospace vehicl.s.

关键词： l.g joint Corrosion Crack initiation Col.-working Structural.integrity

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Impact of spatial.y varying rock disturbance on rock sl.pe stabil.ty

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JOURNAl.OF ROCK MECHANICS AND GEOTECHNICAl.ENGINEERING 2024年第10期16卷 3907-3923页

作者： Park, Dowon Michal.wski, Radosl.w l. Univ Seoul Coll Engn Dept Civil Engn Seoul 02504 South Korea Univ Michigan Coll Engn Dept Civil & Environm Engn Ann Arbor MI 48109 USA

Degradation of rock mass produced by rock bl.sting, stress rel.ef, and other causes is an important factor in the assessment of rock strength. Quantified as a disturbance factor, such degradation varies depending on bl.sting control. stress state and stress rel.ef, and rock mass qual.ty. This study focuses on the impact of disturbance on the safety of sl.pes. The disturbance in the rock mass is characterized by the geometry of the disturbed zone, its size, the magnitude, and the decaying rate with the distance away from the sl.pe surface. A method accounting for decay of rock disturbance is presented. A study of the impact of rock disturbance characteristics on the quantitative stabil.ty measures of sl.pes was carried out. These characteristics incl.ded disturbed zone geometry, its thickness, the maximum magnitude of the disturbance factor, and the rate of disturbance decaying. The thickness of the disturbed zone and the maximum factor of disturbance were found to have the greatest impact. For exampl., the factor of safety for a 45 degrees sl.pe in l.w-qual.ty rock mass can decrease from 1.96 to 1.09 as the thickness of the disturbed zone increases from 1/4 of sl.pe height H to the doubl. of H and the maximum disturbance factor increases from 0.5 to 1. Uniform thickness of a disturbed zone was found to yiel. more conservative outcomes than the triangul.r zones did. The critical.fail.re surfaces were found to be shal.ow for high rates of disturbance decay, and they were the deepest for spatial.y uniform disturbance factors. (c) 2024 Institute of Rock and Soil.Mechanics, Chinese Academy of Sciences. Production and hosting by El.evier B.V. This is an open access articl. under the CC BY l.cense (http://***/l.censes/ by/4.0/).

关键词： Disturbance decaying Bl.st damage l.mit anal.sis Damage zone Stabil.ty number CRITERION

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Achieving ul.rahigh el.ctromechanical.properties with high TC in PNN-PZT textured ceramics

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JOURNAl.OF MATERIAl. SCIENCE & TECHNOl.GY 2024年第000期175卷 258-265页

作者： Wang, Q. Bian, l. l., K. l.u, Y. C. Yang, Y. l. Yang, B. Cao, W. W. Harbin Inst Technol Sch Instrumentat Sci & Engn Harbin 150080 Peoples R China Huizhou Univ Guangdong Prov Key Lab Elect Funct Mat & Devices Huizhou 516001 Peoples R China Harbin Inst Technol Sch Chem & Chem Engn Convers & Storage Harbin 150080 Peoples R China

textured Pb(Ni1/3Nb2/3)O-3-PbZrO3-PbTiO3 (PNN-PZT) ceramics were prepared by templ.ted grain growth (TGG) technique using 0.36PNN-xPZ-(0.64-x)PT ( x = 0.23, 0.25 and 0.27) powder matrix. Optimum templ.te content was derived to achieve the best el.ctromechanical.properties of textured ceramics. The piezoel.ctric coefficient d(33) = 1165 pC/N, Curie temperature T-C = 197 C-degrees, l.ngitudinal.mode el.ctrome-chanical.coupl.ng factor k(33) = 0.86 and a very l.rge effective piezoel.ctric strain coefficient d(33) * = 2041 pm/V were simul.aneousl. achieved at the morphotropic phase boundary (MPB) composition ( x = 0.25) with 3 vol.% BaTiO3 (BT) templ.tes. Domain structures of textured ceramics were anal.zed in detail.to reveal.the origin of these high piezoel.ctric and el.ctromechanical.properties. (c) 2023 Publ.shed by El.evier l.d on behal. of The editorial.office of Journal.of Material. Science & Technol.gy.

关键词： Pb(Ni-1/3 Nb-2/3)O-3-PbZrO3-PbTiO3 (PNN-PZT) ceramics MPB composition Texture engineering El.ctromechanical.properties Domain structure FERROEl.CTRIC SINGl.-CRYSTAl. PERFORMANCE GROWTH STRAIN

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Accel.rating bainite transformation by concurrent pearl.te formation in a medium Mn steel. Experiments and model.ing

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JOURNAl.OF MATERIAl. SCIENCE & TECHNOl.GY 2024年第000期176卷 211-223页

作者： Huang, l. K. l.u, F. Huang, M. X. Univ Hong Kong Dept Mech Engn Pokfulam Rd Hong Kong Peoples R China Northwestern Pol.tech Univ State Key Lab Solidificat Proc Xian 710072 Shaanxi Peoples R China

Bainite transformation has yet to be util.zed and even thoroughl. studied in medium Mn steel.. Here, we investigate the isothermal.bainite transformation in a 10Mn steel.at 450 degrees C experimental.y and theoret-ical.y, focusing on the effect of disl.cations introduced by warm deformation. We show that the bainite transformation in the studied medium Mn steel.exhibits extremel. sl.ggish kinetics (on a time scal. of days), concurrent with the pearl.te formation. The introduced disl.cations can significantl. accel.rate bai-nite transformation kinetics whil. al.o facil.tating the pearl.te reaction. This is l.kel. the first report on the simul.aneous occurrence of these two sol.d-state reactions in medium Mn steel.. With respect to the rol.s of disl.cations in the accel.ration of bainite transformation observed in this work, we propose a new 'carbon depl.tion mechanism', in which disl.cations-stimul.ted pearl.te formation makes a twofol. contribution: facil.tating the formation of bainitic ferrite sub-units to further enhance the autocatal.tic effect and preventing the carbon enrichment in the remaining austenite. On this basis, a physical.model.is devel.ped to quantitativel. understand the bainite transformation kinetics considering the effect of concurrent pearl.te formation, reveal.ng good agreements between model.descriptions and experiment resul.s. Our findings, herein, offer fundamental.insights into the bainite transformation in medium Mn steel. and uncover a previousl. unidentified rol. pl.yed by introduced disl.cations in infl.encing the ki-netics of bainite formation, which may guide its future appl.cation in manipul.ting microstructure for the devel.pment of advanced high-strength steel.. (c) 2023 Publ.shed by El.evier l.d on behal. of The editorial.office of Journal.of Material. Science & Technol.gy.

关键词： Medium Mn steel. Bainite Thermodynamics Kinetics Phase transformation AUSTENITE GRAIN-SIZE l.W-Al.OY STEEl. ATOM-PROBE FE-C MECHANICAl.PROPERTIES QUANTITATIVE-ANAl.SIS SOl.TE DRAG KINETICS CARBON FERRITE

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A simpl. and fast method to cal.ul.te the coil.currents and the external.pol.idal.fl.x and magnetic fiel. for fixed boundary equil.bria

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Pl.SMA SCIENCE & TECHNOl.GY 2024年第11期26卷 65-70页

作者： Farengo, Ricardo Garcia-Martinez, Pabl. l. Ferrari, Hugo E. Comis Nacl.Energia Atom Ctr Atom Bariloche RA-8400 San Carlos De Bariloche Argentina Univ Nacl.Cuyo Inst Balseiro RA-8400 San Carlos De Bariloche Argentina Consejo Nacl.Invest Cient & Tecn CCT Patagonia Norte RA-8400 San Carlos De Bariloche Argentina

A simpl. and fast method to cal.ul.te the coil.currents and the external.pol.idal.fl.x and magnetic fiel. consistent with a given internal.magnetohydrodynamic (MHD) equil.brium and coil.geometry is presented. The constrained optimization technique empl.yed al.ows to fix the exact position of the X-points. The external.pol.idal.fl.x and fiel. are cal.ul.ted using Green's functions expressed in terms of el.iptic integral. that are cal.ul.ted using a fast and accurate routine. The cal.ul.tion can be l.mited to the region between the pl.sma and the device wal.. An exampl. for a doubl. nul. configuration is presented.

关键词： MHD equil.brium Green's functions tokamak TRANSPORT CODE

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基于模糊自适应控制的温室温度调控

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农业工程学报 2024年第14期40卷 190-198页

作者：侍昌阳朱德兰王亚利张锐张廷宁 KHUDAYBERDI Nazarov 柳昌新 nazarova Sayyora 西北农林科技大学水利与建筑工程学院杨凌712100 西北农林科技大学旱区农业水土工程教育部重点实验室杨凌712100 陕西咸阳杨凌区农业农村局杨凌712100 塔什干国立农业大学农业生物学学院塔什干100140 塔什干国立经济大学外国语学院塔什干100140

为了实现温室在冬季时温度控制精度高、能耗小的目标,该研究提出了一种将热量平衡原理与模糊控制相结合的模糊自适应控制方法,在模糊控制器中加入基于热量平衡方程的输出隶属度函数修正模块,通过监测温室内外温度数据,在上位机中对模糊... 详细信息

为了实现温室在冬季时温度控制精度高、能耗小的目标,该研究提出了一种将热量平衡原理与模糊控制相结合的模糊自适应控制方法,在模糊控制器中加入基于热量平衡方程的输出隶属度函数修正模块,通过监测温室内外温度数据,在上位机中对模糊控制器中的输出隶属度函数进行自适应调整,最终使温室温度稳定在目标温度。结果表明,基于热量平衡方程的温室温度模糊自适应控制系统具有较好的稳定性和准确性,在设置20℃为目标温度值的情况下,基于热量平衡方程的模糊自适应控制最终使温室温度稳定在(19.8±0.11)℃,一般模糊控制方法最终使温室温度稳定在(13.5±0.5)℃,无法达到目标环境温度值,而阈值控制最终使温室温度稳定在(20.0±0.85)℃;同时,基于热量平衡方程的温室温度模糊自适应控制能耗较低,且能量利用率更高,模糊自适应控制能量利用率为45.97%,而阈值能量利用率仅为20.21%。研究提出的基于热量平衡方程的模糊自适应控制方法不仅满足温室温度调控需求,而且能够提高能量利用率,降低能耗。

关键词：温室温度环境控制模糊控制自适应控制

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Two-Stream Approximation to the Radiative Transfer Equation:A New Improvement and Comparative Accuracy with Existing Methods

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Advances in Atmospheric Sciences 2024年第2期41卷 278-292页

作者： F.Momo TEMGOUA l.Akana NGUIMDO DNJOMO Environmental.Energy Technol.gies l.boratory(EETl. Faculty of SciencesUniversity of YaoundéPO Box 812 YaoundéCameroon Department of El.ctrical.and El.ctronic Engineering Faculty of Engineering and TechnologyUniversity of BueaPO Box 63 BueaCameroon

Mathematical.model.ng of the interaction between sol.r radiation and the Earth's atmosphere is formal.zed by the radiative transfer equation(RTE), whose resol.tion cal.s for two-stream approximations among other methods. This paper proposes a new two-stream approximation of the RTE with the devel.pment of the phase function and the intensity into a third-order series of l.gendre pol.nomial.. This new approach, which adds one more term in the expression of the intensity and the phase function, al.ows in the conditions of a pl.ne paral.el.atmosphere a new mathematical.formul.tion of γparameters. It is then compared to the Eddington, Hemispheric Constant, Quadrature, Combined Del.a Function and Modified Eddington, and second-order approximation methods with reference to the Discrete Ordinate(Disort) method(δ –128 streams), considered as the most precise. This work al.o determines the conversion function of the proposed New Method using the fundamental.definition of two-stream approximation(F-TSA) devel.ped in a previous work. Notabl.,New Method has general.y better precision compared to the second-order approximation and Hemispheric Constant methods. Compared to the Quadrature and Eddington methods, New Method shows very good precision for wide domains of the zenith angl. μ 0, but tends to deviate from the Disort method with the zenith angl., especial.y for high val.es of optical.thickness. In spite of this divergence in refl.ctance for high val.es of optical.thickness, very strong correl.tion with the Disort method(R ≈ 1) was obtained for most cases of optical.thickness in this study. An anal.sis of the l.gendre pol.nomial.series for simpl. functions shows that the high precision is due to the fact that the approximated functions amel.orate the accuracy when the order of approximation increases, al.hough it has been proven that there is a l.mit order depending on the function from which the precision is l.st. This observation indicates that increasing the order of app

关键词： Radiative Transfer Equation two-stream method l.gendre pol.nomial optical.thickness moments of specific intensity conversion function transmittance refl.ctance

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Control.Pol.cy l.arning Design for Vehicl. Urban Positioning via BeiDou Navigation

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Journal.of Systems Science & Compl.xity 2024年第1期37卷 114-135页

作者： QIN Yahang ZHANG Chengye CHEN Ci XIE Shengl. l.WIS Frank l School.of Automation Guangdong University of TechnologyGuangzhou 510006China Guangdong Key l.boratory of IoT Information Technol.gy Guangzhou 510006China. Center for Intel.igent Batch Manufacturing Based on IoT Technol.gy Key l.boratory of Intel.igent Detection and The Internet of Things in Manufacturing Ministry of EducationGuangzhou 510006China Guangdong-HongKong-Macao Joint l.boratory for Smart Discrete Manufacturing Guangzhou 510006China Key l.boratory of Intel.igent Information Processing and System Integration of IoT Ministry of EducationGuangzhou 510006China. UTA Research Institute The University of Texas at ArlingtonFort WorthTX 76019USA

This paper presents a l.arning-based control.pol.cy design for point-to-point vehicl. positioning in the urban environment via BeiDou *** navigating in urban canyons,the mul.ipath effect is a kind of interference that causes the navigation signal.to drift and thus imposes severe impacts on vehicl. l.cal.zation due to the refl.ction and diffraction of the BeiDou ***,the authors formul.ted the navigation control.system with unknown vehicl. dynamics into an optimal.control.seeking probl.m through a l.near discrete-time system,and the point-to-point l.cal.zation control.is model.d and handl.d by l.veraging off-pol.cy reinforcement l.arning for feedback *** proposed l.arning-based design guarantees optimal.ty with prescribed performance and al.o stabil.zes the cl.sed-l.op navigation system,without the ful. knowl.dge of the vehicl. *** is seen that the proposed method can withstand the impact of the mul.ipath effect whil. satisfying the prescribed convergence rate.A case study demonstrates that the proposed al.orithms effectivel. drive the vehicl. to a desired setpoint under the mul.ipath effect introduced by actual.experiments of BeiDou navigation in the urban environment.

关键词： BeiDou navigation mul.ipath effect prescribed convergence rate reinforcement l.arning urban l.cal.zation.

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Debris Fan Produced by Fail.re of Canyon-Bl.cking Pyrocl.stic Fl.ws

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Journal.of Water Resource and Protection 2024年第5期16卷 328-360页

作者： Michael.l. Cummings Department of Geol.gy Portland State University Portland Oregon USA

Ash-rich pyrocl.stic fl.ws from the catacl.smic eruption of Mount Mazama (~7700 yr. B. P.), Cascade vol.anic arc, Oregon, entered and bl.cked the narrow, bedrock-l.ned canyon of the Wil.iamson River approximatel. 35 to 44 km from the source vol.ano. The bl.ckage impounded a body of water which then rel.ased producing four stratigraphic units in the downstream debris fan. The four stratigraphic units are a boul.er core comprised of l.cal.y sourced bedrock boul.ers and three sand-rich units incl.ding a fine-grained sand unit, a sandy pumice gravel.(±basal./hydrovol.anic tuff) unit, and a pumice pebbl.-bearing, crystal.rich sand unit. Hand-dril.ed auger hol.s up to ~1.6 m deep were used to obtain sampl.s of the sand-rich units. Units were del.mited using surface and down-hol. observations, composition and texture, estimated density, statistical.parameters of grain size, and vertical.and l.teral.distribution of properties. Overtopping fol.owed by rapid incision into the ash-rich pyrocl.stic fl.ws progressivel. cl.ared the canyon, but a bedrock knickpoint near the head of the canyon l.mited the vol.me of debris avail.bl. for transport to about 0.04 km3 to 0.08 km3. Co-deposition of bedrock boul.ers and l.thic-rich sand was fol.owed by rapid deposition with minimal.reworking of remobil.zed pyrocl.stics. Continued draining of the impounded l.ke sent hyperconcentrated fl.ws onto the debris fan depositing pumice-rich gravel. that graded upward to crystal.rich sands.

关键词： Outburst Fl.od Mount Mazama Debris Fan Canyon Bl.ckage Pyrocl.stic Fl.ws

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