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Response of an old landslide to reservoir filling: A case history

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Science china(Technological Sciences) 2005年第z1期48卷 27-32页

作者： L.g. Tham c.f. Lee Department of civil Engineering University of Hong Kong Hong Kong China

Unfavorable hydrodynamic evolution is considered as the major cause leading to reservoir slope instability and is often modeled by numerical method. However, this simulation is seldom checked by systematic field instrumentation. Taking the opportunity of filling the Three gorges Reservoir, a system was established in Xietan landslide to monitor reservoir water level, subground water level, seepage pressure, rainfall and deformation, etc. The monitored data during reservoir filling shows that: (1) The water level rise in the bank lags behind the reservoir filling and the lag time depends on the bank permeability; (2) rainfall-induced subground water rise and its lag time is closely correlated to hourly rainfall, indicating that it is not feasible or sufficient to use daily rainfall for analysis; (3) the effect of inverse seepage during reservoir filling on stability is ephemeral and reservoir filling is the major cause leading to bank instability.

关键词： reservoir filling, old landslide, monitoring system, water level, deformation.

Damage detection on framed structures: modal curvature evaluation using Stockwell Transform under seismic excitation

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Earthquake Engineering and Engineering Vibration 2015年第2期14卷 265-274页

作者： R.Ditommaso f.c.Ponzo g.Auletta Department of Structures Geotechnics Engineering Geology University of Basilicata School of Engineering University of Basilicata

The key parameters for damage detection and localization are eigenfrequencies, related equivalent viscous damping.f.c.ors and mode shapes. The classical approach is based on the evaluation of these structural parameters before and after a seismic event, but by using a modern approach based on time-frequency transformations it is possible to quantify these parameters throughout the ground shaking phase. In particular with the use of the S-Transform, it is possible to follow the temporal evolution of the structural dynamics parameters before, during and after an earthquake. In this paper, a methodology for damage localization on framed structures subjected to strong motion earthquakes is proposed based on monitoring the modal curvature variation in the natural frequency of a structure. Two examples of application are described to illustrate the technique: computer simulation of the nonlinear response of a model, and several laboratory(shaking table) tests performed at the University of Basilicata(Italy). Damage detected using the proposed approach and damage revealed via visual inspections in the tests are compared.

关键词： damage detection S-transform band-variable fi lter

On the friction effects on rigid-body penetration in concrete and aluminium-alloy targets

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Defence Technology（防务技术） 2019年第4期15卷 576-581页

作者： c.g. chai A.g. Pi Q.M. Li f.L. Huang Institute of chemical Materials China Academy of Engineering Physics Mianyang Sichuan 621900 China State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing 100081 China School of Mechanical Aerospace and Civil Engineering University of Manchester Manchester M13 9PL UK

The friction on the projectile shank is usually excluded in the penetration analysis due to the difficulties to measure the pressure and frictional *** this article,the frictional force on projectile shank is discussed indirectly through the comparison between experimental data and empirical/analytical formulas of the penetration depth for both concrete and aluminium-alloy *** is found that the effect of the frictional force along the projectile shank can be further discussed by the afore comparison and discussion and cannot be ignored because of the relatively large effecting area,especially for deep penetration of concrete and aluminium-alloy targets,where the friction will account for more proportion of penetration resistance.

关键词： Penetration friction concrete Aluminium

A node-based smoothed point interpolation method for dynamic analysis of rotating flexible beams

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Acta Mechanica Sinica 2018年第2期34卷 409-420页

作者： c.f.Du D.g.Zhang L.Li g.R.Liu college of civil Science and Engineering Yangzhou University School of Sciences Nanjing University of Science and Technology School of Aerospace Systems University of Cincinnati

We proposed a mesh-free method, the called node-based smoothed point interpolation method(NS-PIM),for dynamic analysis of rotating beams. A gradient smoothing technique is used, and the requirements on the consistence of the displacement functions are further weakened. In static problems, the beams with three types of boundary conditions are analyzed, and the results are compared with the exact solution, which shows the effectiveness of this method and can provide an upper bound solution for the *** means that the NS-PIM makes the system soften. The NS-PIM is then further extended for solving a rigid-flexible coupled system dynamics problem, considering a rotating flexible cantilever beam. In this case, the rotating flexible cantilever beam considers not only the transverse deformations,but also the longitudinal deformations. The rigid-flexible coupled dynamic equations of the system are derived via employing Lagrange’s equations of the second type. Simulation results of the NS-PIM are compared with those obtained using finite element method(fEM) and assumed mode method. It is found that compared with fEM, the NS-PIM has anti-ill solving ability under the same calculation conditions.

关键词： Meshfree method NS-PIM Rigid-flexible coupled system dynamics Rotating beams Dynamic response

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Acta Mechanica Sinica 2020年第6期36卷 1294-1301,I0003页

作者： c.g.chai A.g.Pi Q.M.Li f.L.Huang Institute of chemical Materials China Academy of Engineering PhysicsMianyang621900China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China School of Mechanical Aerospace and Civil EngineeringUniversity of ManchesterManchesterM139PLUK

Similarity can reflect common laws in the mechanism of rigid-body *** this paper,the similarities in rigid-body penetration depth are demonstrated by three non-dimensional but physically meaningful quantities,i.e.,ρkinetic,I∗ln and N′*** three quantities represent the non-dimensional areal density of projectile kinetic energy,the effect of nose geometry,and the friction at the interactive cross section between projectile and target *** is shown that experimental data of rigid projectile penetration,from shallow to deep penetration,can be uniquely unified by these three similarity quantities and their ***,for ogival nose projectiles,their penetration capacities are dominated byρkinetic,which is consisted by non-dimensional effective length Leff and non-dimensional quantity Dpn=ρpv20AY which has the same form as Johnson’s damage *** the sacrifice of minor theoretical accuracy,the non-dimensional penetration depth P/d can be understood as directly controlled by Dpn,enhanced by projectile effective length Leff under a multiplication relation,and optimized by projectile nose geometry in the formation of I∗ln.

关键词： concrete target Deep penetration Similarity-Johnson's damage number

The role of rhizobacteria in rice plants: growth and mitigation of toxicity

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Journal of Integrative Agriculture 2018年第12期17卷 2636-2647页

作者： Marcela c f Rêgo Aline f cardoso Thayná da c ferreira Marta c c de filippi Telma f V Batista Rafael g Viana gisele B da Silva Plant Protection Laboratory Institute of Agrarian Sciences Federal Rural University of Amazon Phytopathology Laboratory Brazilian Enterprise for Agricultural Research-Rice and Beans

Allelopathic compounds reduce the growth and productivity of upland rice plants, especially in consecutive plantations. The rhizobacteria Pseudomonas fluorescens BRM-32111 and Burkholderia pyrrocinia BRM-32113 have been recorded as growth promoters in rice. This study was developed to understand the effect of the application of rhizobacteria on upland rice plants in consecutive plantations. Experiments were conducted in a completely randomized design with four replications of four treatments: rice seed inoculated with P. fluorescens BRM-32111, rice seed inoculated with B. pyrrocinia BRM-32113(both sown on soil with rice residue), non-inoculated plants sown on soil with rice residue(control with residue(WR)), and non-inoculated plants on soil with no residue(NR). Roots and seedling growth were adversely affected by allelopathic compounds in control WR plants. Plants inoculated with rhizobacteria P. fluorescens BRM-32111 or B. pyrrocinia BRM-32113 induced an increase of 88% in biomass, 3% in the leaf area, 40% in length, 67% in root biomass, 21% in chlorophyll a, 53% in chlorophyll(a+b), 50% in rate of carbon assimilation(A), 227% in A/rubisco carboxylation efficiency(ci) and 63% in water use efficiency(WUE) compared to control WR plants. These results indicate that rhizobacteria P. fluorescens BRM-32111 and B. pyrrocinia BRM-32113 increase the tolerance of rice plants to stress from allelochemicals. There are possible practical agricultural applications of these results for mitigating the effects of environmental allelochemistry on upland rice.

关键词： allelopathy B.pyrrocinia P.fluorescens rhizobacteria rice

Assessing reservoir connectivity with pressure/rate surveillance data

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Petroleum Science 2023年第2期20卷 1077-1086页

作者： g.f.J.Al-Khmaysawee Z.Reza c.S.Kabir Missouri University of Sci.&Tech. RollaMOUSA University of Oklahoma NormanOKUSA Incendium Technologies Round RockTXUSA

Estimating reservoir connectivity is critical for assessing infill-drilling prospects and initiating fluid injection in enhanced oil recovery operations. Several methods have appeared in the literature over decades to meet these business needs, given that all tools, including seismic imaging, have limitations. Besides imaging, geochemical fingerprinting constitutes a powerful tool to gauge the compartmentalization question. However, real-time pressure/rate surveillance data allows assessing interwell connectivity vis-à-vis the overall drainage *** study presents a simplified approach to using the reciprocal-productivity index (RPI) vs. the total-material-balance time (tTMB) plot. This tool exhibits the same slope for those wells in the same compartment beyond the start of the boundary-dominated flow (BDf) period. The wells showing different slopes imply that they are in separate drainage volumes. The early-time transient period remains muted to minimize confusion on this cartesian plot. We validated the proposed tool's efficacy with 2D and 3D models with increased degrees of reservoir complexity, followed by the verification phase with four field examples. The use of other analytical tools complemented our findings.

关键词： Reservoir compartmentalization Reciprocal-productivity index Total material-balance time Analysis of boundary-dominated flow period

Erbium photoluminescence response related to nanoscale heterogeneities in sol-gel silicates

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Journal of Rare Earths 2013年第1期31卷 18-26页

作者： H.c.Vasconcelos M.g.Meirelles f.Rivera-López Department of Technological Sciences and Development Azores University cEfITEc-centre of Physics and Technological Research Physics Department of FCT/UNL Department of fundamental and Experimental Physics Electronics and SystemsUniversity of La Laguna

Sol-gel glassy films of the SiO2-TiO2-PO2.5-ErO2.5 system containing nanocrystallites of ErPO4, were obtained through suitable heat treatments. Variations in the shape and intensity of the Er3＋ photoluminescent signal around 1500 nm were linked to the nature of the host environment of the active ions; the specific features of the photoluminescent emission spectrum of the erbium 4113/2 metastable level were interpreted in terms of structural changes in the glassy films. The photoluminescent spectrum was found to be sensitive to the order （crystalline） or disorder （amorphous） of the Er3＋ ions neighbour within the glassy matrix. An amorphous envi- ronment led to a broadening of Er3＋ PL emission band while a crystalline one was responsible for a drastic photoluminescent band- width narrowing. The presence of nanoscale heterogeneities caused a drastic photoluminescence intensity decrease. changes in the shape of the decay curve of fluorescence lifetime were found also structurally dependent on volumetric defects, occurrence of phase separation and Er3＋-Er3＋ clustering effects as well.

关键词： sol-gel Er3+ optical probe nanoscale heterogeneities photoluminescence ErPO4 rare earths

New method for rekindling the explosive waves in Maxwellian space plasmas

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Plasma Science and Technology 2020年第12期22卷 48-58页

作者： g c DAS Kalikadas Road Byelane HazraparaCoochbehar-736101West BengalIndia

Our interest is to study the nonlinear wave phenomena in complex plasma constituents with Maxwellian electrons and ions. The main aim is to use a new method known as the(g′/g)method to exhibit the effects of dust charge fluctuations on the evolution of nonlinear waves. The coherent features of the shock and solitary waves along with the generation of high-energy waves have been amplified through the solution of the Korteweg–de Vries–Burgers equation,and the different natures of the waves were found successfully. Results are discussed graphically with the thoughtful choice of typical plasma parameters from different space plasma environments, exactly those found in cosmic dusty plasmas laden in ionospheric auroral region,radial spokes of Saturn's rings, planetary nebulae and solar f-corona region. All conclusions are in good accordance with the actual occurrences and could be of interest to further investigations of space. Moreover, the applicability of the present method is hoped to be a great enhancement by its use as ingenious mechanism used to evaluate the soliton dynamics and Burgers shock waves.

关键词： Maxwellian complex plasma nonlinear waves soliton and shock propagation (g′/g)method space plasmas