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Pedosphere 2009年第5期19卷 631-641页

作者： m.J.KHAN D.l.JONES Department of Soil and Environmental Sciences NWFP Agricultural UniversityPeshawar(Pakistan) School of Agricultural and Forest Sciences University of WalesBangorGwynedd LL57 2UW(UK)

Soil samples from a historic copper mine tailing site at the Parys mountain,North Wales(UK) were amended with green waste compost(GC),GC+30% sewage sludge(GCS),lime and diammonium phosphate(DAP),to determine the effect of amendments on DTPA-and Ca(NO3)2-extractable metals in the mine tailing and on the phytoavailability of heavy metals by a lettuce(lactuca sativa l.).Both compost were added at the rate of 10% by weight,lime was added as calcium carbonate equivalent(pH = 7) and DAP at a 2300 mg kg-1 soil *** experiment was arranged in randomised complete design with three replicates in pots under control *** of lime resulted in the largest reduction in metal extractability with DTPA and Ca(NO3)2 and phytoavailability of Cu,Fe and Zn while DAP was effective in lowering Pb extractability and *** exception of Zn,all other metals extracted decreased with time after amendment *** distribution of heavy metals between and within the four procedures of potentially bioavailable sequential extraction(PBASE) varied significantly(P lationships were noted between the metals extracted with PBASE SE1 and Cu,Pb(P lts indicate that addition of lime is sufficient to restore the vegetative cover to a high metal mine waste while DAP is good for stabilizing Pb,but its detrimental role on plant growth and the risk associated with presence of N in DAP(through N leaching) may restrict its chances for remediation of contaminated sites.

关键词： lettuce metal uptake potentially bioavailable sequential extraction

High energy neutron and pion-decay gamma-ray emissions from solar flares

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Chinese Journal of Astronomy and Astrophysics 2009年第1期9卷 11-40页

作者： Edward l.Chupp James m.Ryan Physics Department and Space Science Center in the Institute for the Study of Earth Oceans and Space University of New Hampshire

Solar flare gamma-ray emissions from energetic ions and electrons have been detected and measured to GeV energies since 1980. In addition, neutrons produced in solar flares with 100 meV to GeV energies have been observed at the Earth. These emissions are produced by the highest energy ions and electrons accelerated at the Sun and they provide our only direct （albeit secondary） knowledge about the properties of the accelerator（s） acting in a solar flare. The solar flares, which have direct evidence for pion-decay gamma-rays, are unique and are the focus of this paper. We review our current knowledge of the highest energy solar emissions, and how the characteristics of the acceleration process are deduced from the observations. Results from the RHESSI, INTEGRAl and CORONAS missions will also be covered. The review will also cover the solar flare capabilities of the new mission, FERmI GAmmA RAY SPACE TElESCOPE, launched on 2008 June II. Finally, we discuss the requirements for future missions to advance this vital area of solar flare physics.

关键词： Sun -- Flares -- Particle Acceleration-meson Production

Non-axisymmetric Homann stagnation-point flow of Walter’s B nanofluid over a cylindrical disk

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Applied mathematics and mechanics(English Edition) 2020年第5期41卷 725-740页

作者： m.KHAN m.SARFRAZ J.AHmED l.AHmAD C.FETECAU Department of mathematics Quaid-i-Azam UniversityTaxila 47050Pakistan Department of Basic Sciences University of Engineering and TechnologySheringal Upper Dir 18000Pakistan Department of mathematics Shaheed Benazir Bhutto UniversitySheringal Upper Dir 18000Pakistan Academy of Romanian Scientists Bucuresti 050094Romania

The study of non-axisymmetric Homann stagnation-point flow of Walter’s B nanofluid along with magnetohydrodynamic(mHD) and non-linear Rosseland thermal radiation over a cylindrical disk in the existence of the time-independent free stream is considered. moreover, the notable impacts of thermophoresis and Brownian motion are analyzed by Buongiorno’s model. The momentum, energy, and concentration equations are converted into the dimensionless coupled ordinary differential equations via similarity transformations, which are later numerically solved by altering the values of the pertinent parameters. The numerical and asymptotic solutions for the large shear-to-strain rate ratio γ =a/bfor the parameters of the displacement thicknesses and the wall-shear stress are computed by perturbative expansion and analyzed. Furthermore, the technique bvp4c in mATlAB is deployed as an efficient method to analyze the calculations for the non-dimensional velocities, temperature, displacement thickness, and concentration profiles. It is observed that the two-dimensional displacement thickness parameters α andβ are reduced due to the viscoelasticity and magnetic field effects. moreover, when the shear-to-strain rate ratio approaches infinity, α is closer to its asymptotic value, while βand the three-dimensional displacement thickness parameter δ1 show the opposite *** outcomes of the viscoelasticity and the magnetic field on the skin friction are also determined. It is concluded that ■ reaches its asymptotic behavior when the shearto-strain rate ratio approaches infinity. meanwhile, ■ shows different results.

关键词： Walter’s B fluid cylindrical disk nanofluid magnetic field non-linear thermal radiation stagnation-point flow

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

Advances in the management of infertility in men with spinal cord injury

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Asian Journal of Andrology 2016年第3期18卷 382-390,I0007,I0008页

作者： Emad Ibrahim Nancy l Brackett Charles m lynne The miami Project to Cure Paralysis University of Miami Miller School of Medicine Miami FL USA Department of Urology University of Miami Miller School of Medicine Miami FL USA.

Couples with a spinal cord injured male partner require assisted ejaculation techniques to collect semen that can then be further used in various assisted reproductive technology methods to achieve a pregnancy. The majority of men sustaining a spinal cord injury regardless of the cause or the level of injury cannot ejaculate during sexual intercourse. Only a small minority can ejaculate by masturbation. Penile vibratory stimulation and electroejaculation are the two most common methods used to retrieve sperm. Other techniques such as prostatic massage and the adjunct application of other medications can be used, but the results are inconsistent. Surgical sperm retrieval should be considered as a last resort if all other methods fail. Special attention must be paid to patients with T6 and rostral levels of injury due to the risk of autonomic dysreflexia resulting from stimulation below the level of injury. Bladder preparation should be performed before stimulation if retrograde ejaculation is anticipated. Erectile dysfunction is ubiquitous in the spinal cord injured population but is usually easily managed and does not pose a barrier to semen retrieval in these men. Semen analysis parameters of men with spinal cord injury are unique for this population regardless of the method of retrieval, generally presenting as normal sperm concentration but abnormally low sperm motility and viability. When sperm retrieval is desired in this population, emphasis should be placed on initially trying the simple methods of penile vibratory stimulation or electroejaculation before resorting to more advanced and invasive surgical procedures.

关键词： assisted reproductive technology ejaculation electroejaculation male infertility paraplegia penile vibratory stimulation semen sperm spinal cord injury surgical sperm retrieval

Analysis and design of axially loaded piles in rock

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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

Geochemical evidences of trace metal anomalies for finding hydrocarbon microseepage in the petroliferous regions of the Tatipaka and Pasarlapudi areas of Krishna Godavari Basin,India

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Petroleum Science 2013年第1期10卷 19-29页

作者： Rasheed m A lakshmi m Rao P l S Kalpana m S Dayal A m Patil D J microbiology laboratory Petroleum Geochemistry Group National Geophysical Research Institute (Council of Scientific and Industrial Research)

The long-term seepage of hydrocarbons, either as macroseepage or microseepage, can set up near-surface oxidation reduction zones that favor the development of a diverse array of chemical and mineralogical changes. The bacterial oxidation of light hydrocarbons can directly or indirectly bring about significant changes in the values of pH and Eh of the surrounding environment, thereby also changing the stability fields of the different mineral species present in that environment. The paper reports the role of hydrocarbon microseepage in surface alterations of trace metal concentrations. In this study trace metal alterations were mapped that appear to be associated with hydrocarbon microseepages in the oil/ gas fields. A total of 50 soil samples were collected near oil and gas fields of the Tatipaka and Pasarlapudi areas of the Krishna Godavari Basin, Andhra Pradesh. The soil samples were collected from a depth of 2-2.5 m. The paper reports the chemical alterations associated with trace metals in soils that are related to hydrocarbon microseepages above some of the major oil and gas fields of this petroliferous region. Trace metals, such as scandium （Sc）, vanadium （V）, chromium （Cr）, cobalt （Co）, nickel （Ni）, copper （Cu）, zinc （Zn）, barium （Ba） and strontium （Sr）, in soil samples were analyzed using inductively coupled plasma- mass spectrometry （ICP-mS）. The concentrations of Sc （8 to 40 mg/kg）, V （197 to 489 mg/kg）, Cr （106 to 287 mg/kg）, Co （31 to 52 mg/kg）, Ni （65 to 110 mg/kg）, Cu （88 to 131 mg/kg）, Zn （88 to 471 mg/kg）, Ba （263 to 3,091 mg/kg） and Sr （119 to 218 mg/kg） were obtained. It was observed that the concentrations of trace elements were tremendously increased when they were compared with their normal concentrations in soils. The analysis of adsorbed soil gas showed the presence of high concentrations of YC2＋（C2H6, C3H8 and n-C4H10） ranging from 7 to 222 μg/kg respectively. Integrated studies of trace elements over adsorbed light gaseous hydrocarbons （2C2

关键词： Hydrocarbons microseepage trace metal alterations adsorbed soil gas Krishna Godavari Basin

Interlayer distance effects on absorption coefficient and refraction index change in p-type double-δ-doped GaAs quantum wells

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Chinese Physics B 2019年第12期28卷 186-190页

作者： H Noverola-Gamas l m Gaggero-Sager O Oubram Instituto de Investigaciones en Ciencias Básicas y Aplicadas Universidad Autónoma del Estado de Morelos MorelosCuernavaca 62209Mexico Division Academica de Ingeniería y Arquitectura Universidad Juárez Autonoma de TabascoCunduacan 8660Mexico Centro de Investigación en Ingeniería y Ciencias Aplicadas Universidad Autónoma del Estado de MorelosCuernavaca 62209Mexico Facultad de Ciencias Químicas e Ingeniería Universidad Autónoma del Estado de MorelosCuernavaca 62209Mexico

In the framework of the Thomas–Fermi(TF) approach, a model for the p-type double-δ-doped(DDD) system in Ga As is presented. This model, unlike other works in the literature, takes into account that the Poisson equation associated with the system is nonlinear. The electronic structure is calculated for heavy and light holes. The changes in the electronic structure result of the distance d between the doped layers are studied. In particular, the relative absorption coefficient as well as the relative refractive index change is calculated as a function of the incident photon energy for heavy holes. The effect of the interlayer distance exhibits, in the absorption coefficient, a red shift of the peak position and a decrease in amplitude when the distance increases. In addition, the relative refractive index change node has a red shift as well as the interlayer distance increases. The calculations show that the effect of the separation between layers has a greater influence on the linear terms. These results are very important for theoretical calculations and engineering of optical and electronic devices based in δ-doped Ga As.

关键词： double delta-doping p-type GaAs layers electronic structure Thomas–Fermi approach nonlinear optical properties

Corrosion testing of X52 and X80 steels immersed in stimulated emulsions using a real petroleum sample

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Petroleum Research 2024年第2期9卷 304-316页

作者： l.m.Quej-Ake J.l.Alamilla A.Contreras Instituto mexicano del Petróleo Eje Central Lázaro CárdenasNorte 152San Bartolo AtepehuacanGustavo A.MaderoCiudad de MéxicoC.P.07730México

The aim of this study is to evaluate the internal corrosion process on X52 and X80 steels/real petroleum interfaces containing condensed hydrocarbon plus oilfield-produced water,which were subjected to stimulated emulsions using 50/50 vol ratio mixtures at 45℃,different hydrodynamic conditions,1 h,and 24 h.A washing process by using deionized water was proposed to simulate and identify the corrosiveness of the hydrocarbon phase after 24 h of exposure *** characterization by electrochemical impedance spectroscopy and the monitoring of the polarization curves indicated that X80 steel/oilfield-produced water interfaces were more susceptible to corrosion than X52 steel exposed to oilfield-produced *** combined speed rotation of 600 rpm using a magnetic stirrer+600 rpm using a rotating disk electrode decreased the corrosion rate on X52 *** stimulated emulsions made of hydrocarbon+oilfield-produced water and hydrocarbon+deionized water at 24 h increased the corrosion rate on X80 steel(0.34 mm/year and 0.43 mm/year,respectively),promoting the formation of erosion and pitting *** types of corrosion depended mainly on the physicochemical properties of the hydrocarbon,oilfield-produced water,exposure times,and hydrodynamic systems in which the hydrocarbon was studied.

关键词： Corrosion Emulsions X52 steel X80 steel

A seed and soil model of loneliness in Alzheimer's disease

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Neural Regeneration Research 2024年第12期19卷 2575-2576页

作者： Hannah l.Apostolou Ian m.mcDonough Department of Psychology The University of AlabamaTuscaloosaALUSA Department of Psychology Binghamton UniversityBinghamtonNYUSA

loneliness is classically defined as a result of perceiving a discrepancy between the desired quantity and quality of one's social life and actual social relationships(Perlman and Peplau,1984).lifespan research has indicated older adults are among the highest risk for experiencing loneliness because their social network size decreases more frequently than that of younger adults.

关键词： Alzheimer younger soil