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Analysis and design of axially loaded piles in rock

Journal of Rock Mechanics and Geotechnical Engineering 2019年第3期11卷 535-548页

作者： C.M.Haberfield A.l.E.lochaden Golder Associates Pty.ltd. MelbourneAustralia

Despite significant advancements in in situ test techniques,construction practices,understanding of rock joint and rock mass behaviours,and numerical analysis methods,the design of bored concrete cast-insitu piles in rock is still largely based on the assessment of bearing ***,for many of the rock conditions encountered,the bearing capacity of piles is a nebulous concept and a figment of the designer’s *** if it can be reasonably quantified,it has little,if any,significance to the performance of a pile in *** load carrying capacity of even low strength rock(in most situations)is far in excess of the strength of the structure(for example,a building column)transmitting the *** performance of a pile in rock is usually a displacement issue and is a function of rock mass stiffness rather than rock mass *** addition,poor pile performance is much more likely to result from poor construction practices than excessive displacement of the rock *** occur for footings that are undermined,or where unfavourable structure in the rock allows movement towards a free surface to ***,codes of practices,reference books and other sources of design information should focus foundation design in rock on displacement rather than strength *** investigations should measure rock mass stiffness and defect properties,as well as intact rock *** paper summarises the fundamental concepts relating to performance of piles in rock and provides a basis for displacement focused design of piles in *** also presents comments relating to how piles are modelled in widely used commercial finite element software for soil-structure interaction analysis,within the context of the back-analysis of a pile load test,and proposes recommendations for pile analysis and design.

关键词： Pile design Pile analysis Pile load test Finite element analysis

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Spectra and Spin Polarization of the Valence Band Auger Emission from Cr （100） Surface

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Chinese Physics letters 2003年第10期20卷 1864-1867页

作者：袁建民 l.Fritsche J.Noffke DepartmentofAppliedPhysics NationalUniversityofDefenseTechnologyChangsha410073 InstitutfuerTheoretischePhysik TUClausthalD-38678Clausthal-ZellerfeldF.R.Germany

Calculations have been carried out on spin-polarized Auger electron emission from a seven-layer chromium (100)-film. The core and valence states concerning the Auger transition are obtained from a self-consistent full-potential linearized augmented plane wave calculation by using a repeated slab geometry. The calculations refer to experiments on the l3M23V- and l3VV-transitions that have recently been carried out by Heinzmann et al. The Auger spectrum obtained for the l3VV transition agrees relatively well with our calculations, whereas the observed l3M23V-Auger structure is considerably wider than that predicted by our theory. Nevertheless, the spin-polarization in the latter case, which is about -13%, is in fair agreement with the experiment, different from the l3VV-transition where the experiment yields -10% as opposed to the theoretical value of -25%. We give possible reasons for the origin of these discrepancies.

关键词：光谱自旋极化 Cr(100) 铬表面电子发射价带螺旋发射

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A New North Atlantic Oscillation Index and Its Variability

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Advances in Atmospheric Sciences 2003年第5期20卷 661-676页

作者：李建平 Julian X.l.WANG State Key laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics lASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 Air Resources lab NOAA Silver Spring MD 20910 USA

A new North Atlantic Oscillation (NAO) index, the NAOI, is defined as the differences of normalized sea level pressures regionally zonal-averaged over a broad range of longitudes 80°W-30°E. A comprehensive comparison of six NAO indices indicates that the new NAOI provides a more faithful representation of the spatial-temporal variability associated with the NAO on all timescales. A very high signal-to-noise ratio for the NAOI exists for all seasons, and the life cycle represented by the NAOI describes well the seasonal migration for action centers of the NAO. The NAOI captures a larger fraction of the variance of sea level pressure over the North Atlantic sector (20°-90°N, 80°W-30°E), on average 10% more than any other NAO index. There are quite different relationships between the NAOI and surface air temperature during winter and summer. A novel feature, however, is that the NAOI is significantly negative correlated with surface air temperature over the North Atlantic Ocean between 10°-25°N and 70°-30°W, whether in winter or summer. From 1873, the NAOI exhibits strong interannual and decadal variability. Its interannual variability of the twelve calendar months is obviously phase-locked with the seasonal cycle. Moreover, the annual NAOI exhibits a clearer decadal variability in amplitude than the winter NAOI. An upward trend is found in the annual NAOI between the 1870s and 1910s, while the other winter NAO indices fail to show this tendency. The annual NAOI exhibits a strongly positive epoch of 50 years between 1896 and 1950. After 1950, the variability of the annual NAOI is very similar to that of the winter NAO indices.

关键词： North Atlantic Oscillation (NAO) index interannual and decadal variability signal-to-noise ratio seasonal phase lock

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Ab initio STUDIES ON MAGNETISM OF 3d TRANSITION METAl DIMERS

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Acta Metallurgica Sinica(English letters) 2007年第5期20卷 341-346页

作者： J.H. Gu Z.l. Zhu School of Physical Engineering and Material Physics laboratory Zhengzhou University Zhengzhou 450052 China

Ab initio calculations with the self-consistent full-potential linearized augmented-plane-wave method （FlAPW）, under generalized gradient approximation, have been carried out to describe the electronic and magnetic properties of 3d transition metal dimers. It predicted the antiferromagneticity of Cr2 and ferromagneticity of other species. The Mn2 dimer was shown to be ferromagnetic coupling with a local magnetic moment of 5μB. retaining the value of its free atom state. The V2 and Ni2 exhibited low spin-polarization with local magnetic moment of only 1μB per atom. On the other hand, Fe2 and Co2 were highly spin-polarized with local magnetic moments of 3 and 2μB.

关键词： magnetism 3d transition metal dimer ab initio calculation

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NUMERICAl SIMUlATION OF THE XZ TAURI SUPERSONIC ASTROPHYSICAl JET

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Acta Mathematica Scientia 2009年第6期29卷 1677-1683页

作者： Carl l. Gardner Steven J. Dwyer School of Mathematical and Statistical Sciences Arizona State University Tempe AZ 85287 USA

Computational gas dynamical simulations using the WENO-lF method are applied to modeling the high Mach number astrophysical jet XZ Tauri, including the effects of radiative cooling. Mach 55 simulations of the pulsed proto-jet are presented and analyzed in terms of interacting nonlinear waves： terminal Mach disks, bow shocks, and Meshkov-Richtmyer instabilities of the leading jet contact boundary.

关键词： astrophysical jets ENO. method gas dynamics

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Unsteady generalized Couette flow in composite microchannel

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Applied Mathematics and Mechanics(English Edition) 2011年第1期32卷 23-32页

作者： M.l.KAURANGINI B.K.JHA Department of Mathematical Sciences Kano University of Science and Technology Department of Mathematics Ahmadu Bello University

A numerical study is reported on the fully developed unsteady laminar fluid flow in microchannel parallel-plates partially filled with a uniform porous medium and partially filled with a clear fluid. The flow is induced by the movement of one of the plates and the pressure gradient. The Brinkman-extended Darcy model is utilized to model the flow in the porous region, while the Stokes equation is used in the clear fluid region. A theoretical analysis is also presented for the fully developed steady flow to find closed- form expressions for the interracial velocity and the velocity and skin frictions at the bounding plates. Numerical computations shows excellent agreement between the closedform solutions for fully developed steady flow and the numerical solution to unsteady flow at large values of time.

关键词： unsteady flow composite microchannel

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Current and near-term advances in Earth observation for ecological applications

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Ecological Processes 2021年第1期10卷 1-57页

作者： Susan l.Ustin Elizabeth M.Middleton John Muir Institute of the Environment University of CaliforniaDavisCA 95616USA NASA/Goddard Space Flight Center(Emerita) GreenbeltMD 20771USA.

There is an unprecedented array of new satellite technologies with capabilities for advancing our understanding of ecological processes and the changing composition of the Earth’s biosphere at scales from local plots to the whole *** identified 48 instruments and 13 platforms with multiple instruments that are of broad interest to the environmental sciences that either collected data in the 2000s,were recently launched,or are planned for launch in this *** have restricted our review to instruments that primarily observe terrestrial landscapes or coastal margins and are available under free and open data *** focused on imagers that passively measure wavelengths in the reflected solar and emitted thermal *** suite of instruments we describe measure land surface characteristics,including land cover,but provide a more detailed monitoring of ecosystems,plant communities,and even some species then possible from historic *** newer instruments have potential to greatly improve our understanding of ecosystem functional relationships among plant traits like leaf mass area(lMA),total nitrogen content,and leaf area index(lAI).They provide new information on physiological processes related to photosynthesis,transpiration and respiration,and stress detection,including capabilities to measure key plant and soil biophysical *** include canopy and soil temperature and emissivity,chlorophyll fluorescence,and biogeochemical contents like photosynthetic pigments(e.g.,chlorophylls,carotenoids,and phycobiliproteins from cyanobacteria),water,cellulose,lignin,and nitrogen in foliar *** data will enable us to quantify and characterize various soil properties such as iron content,several types of soil clays,organic matter,and other *** of these satellites are in low Earth orbit(lEO),but we include a few in geostationary orbit(GEO)because of their potential to measure plant physiological traits over diurnal periods,impro

关键词： Terrestrial ecosystems Earth Observing Satellites Ecosystem processes Physiological functions Multispectral Hyperspectral Thermal liDAR Radar imagers Biochemistry Soil properties Species mapping Change detection 3D canopy structure Topography

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Natural variation of hormone levels in Arabidopsis roots and correlations with complex root architecture

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Journal of Integrative Plant Biology 2018年第4期60卷 292-309页

作者： Sangseok lee lidiya l.Sergeeva Dick Vreugdenhil laboratory of Plant Physiology Wageningen University&ResearchDroevendaalsesteeg 16708 PBWageningenThe Netherlands Gyeongsangbuk-Do Agricultural Research&Extension Services Centre 136 Gil-14Chilgokjungang-daeroDaeguSouth Korea

Studies on natural variation are an important tool to unravel the genetic basis of quantitative traits in plants. Despite the significant roles of phytohormones in plant development, including root architecture, hardly any studies have been done to investigate natural variation in endogenous hormone levels in plants. Therefore, in the present study a range of hormones were quantified in root extracts of thirteen Arabidopsis thaliana accessions using a ultra performance liquid chromatography triple quadrupole mass spectrometer. Root system architecture of the set of accessions was quantified, using a new parameter （mature root unit） for complex root systems, and correlated with the phytohormone data. Significant variations in phytohormone levels among the accessions were detected, but were remarkably small, namely less than three-fold difference between extremes. For cytokinins, relatively larger variations were found for ribosides and glucosides, as compared to the free bases. For root phenotyping, length-related traits--lateral root length and total root length--showed larger variations than lateral root number-related ones. For root architecture, antagonistic interactions between hormones, for example, indole-3-acetic acid to trans-zeatin were detected in correlation analysis. These findings provide conclusive evidence for the presence of natural variation in phytohormone levels in Arabidopsis roots, suggesting that quantitative genetic analyses are feasible.

关键词： Natural variation of hormone levels in Arabidopsis roots and correlations with complex root architecture

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Effects of Siraitia grosvenorii extracts on high fat diet-induced obese mice:a comparison with artificial sweetener aspartame

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Food Science and Human Wellness 2022年第4期11卷 865-873页

作者： Ke lü Xiaowan Song Peng Zhang Wei Zhao Ning Zhang Fan Yang Wenqiang Guan Jianfu liu He Huang Chi-Tang Ho Rong Di Hui Zhao Tianjin Key laboratory of Food and Biotechnology School of Biotechnology and Food ScienceTianjin University of CommerceTianjin 300134China Department of Biochemical Engineering School of Chemical Engineering and TechnologyKey Laboratory of Systems BioengineeringMinistry of EducationTianjin UniversityTianjin 300072China Department of Food Science RutgersThe State University of New JerseyNew BrunswickNJ 08901USA Department of Plant Biology RutgersThe State University of New JerseyNew BrunswickNJ 08901USA

long-term artificial sweetener intake is linked to increased risk of obesity. In the present study, supplement of natural sweetener from Siraitia grosvenorii(SG)(or Momordica grosvenorii) fruit, compared with the artificial sweetener aspartame(ASM), was evaluated for anti-obesity effects on mice fed with high fat diet(HFD). We found that, in contrary to ASM, SG extracts prevented body weight gain, the insulin resistance and fat mass accumulation in HFD mice. SG extracts treatment inhibited the infiltration of inflammatory macrophages and lowered the levels of the fat inflammatory cytokines(leptin, macrophage chemoattractant protein 1(MCP-1) and tumor necrosis factor-α(TNF-α)) in adipose tissues. In addition, SG extracts supplement counteracted the remodeling of gut microbiota resulted from HFD. However, ASM supplement aggravated the HFD-induced obese performances, fat inflammation and dysregulation of gut microbiota. Taken together, our results indicate that supplement of SG extracts may represent a promising alternation of artificial sweeteners in preventing metabolic diseases.

关键词： Siraitia grosvenorii High fat diet Obese Inflammation Gut microbiota

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Assessment of locational Compliance Status of Petroleum Products Handling Facilities in Niger Delta Region, Nigeria

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Journal of Environmental Protection 2022年第10期13卷 750-765页

作者： Njideka Jia Ify l. Nwaogazie Prince Mmom Centre for Occupational Health Safety & Environment (COHSE) University of Port Harcourt Port Harcourt Nigeria

This study was aimed at assessing the locational compliance status of petroleum handling facilities in the Niger Delta to the specifications of the Nigerian Upstream Petroleum Regulatory Commission (NUPRC) locational standards. A cross-sectional research design was employed using a Standard checklist of seventeen compliance specifications of NUPRC. A walk-through survey was carried out in 118 identified facilities in three locations: Eket in Akwa-Ibom State, Port Harcourt in Rivers State and Warri in Delta State, respectively. The data obtained were analyzed using inferential and descriptive statistics, Kendall Tau-B and Principal Component analyses. The results indicate that the Petroleum Product facilities complied with 6 (35.29%) out of 17 specifications while 11 (64.70%) specifications were violated. locations compliance of stations in the Niger Delta region is generally poor, but Stations in Port Harcourt recorded a higher compliance rate compared to Eket and Warri. Results of Kendall’s tau-b and Principal Component analysis indicated positive association between all the land space locational compliances. This study attributes the poor compliance rate to rapid urbanization, overpopulation, proliferation of filling stations and poor monitoring by regulatory agencies. It is recommended that, NUPRC should improve its monitoring and enforce regulatory operational specifications.

关键词： locational Compliance Petroleum Handling Stations Monitoring Filling Stations Niger Delta

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