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magnesium Uptake and Palygorskite Transformation Abilities of Wheat and Oat

Pedosphere 2012年第6期22卷 834-841页

作者： m.H.SAlEHI l.TAHAmTANI Department of Soil Science College of AgricultureShahrekord UniversityShahrekord(Iran)

Weathering of clay minerals is a source of nutrients to plants. Palygorskite is a mg-rich fibrous clay mineral that commonly occurs in the soils and sediments of arid regions. Although many studies have examined the environmental conditions required for the formation and stability of palygorskite, information on the transformation of this mineral in the root zone （or rhizosphere） of agricultural crops is limited. This study explored the possibility of palygorskite transformation in the rhizosphere of wheat and oat and compared the ability of these crops to extract structural mg from palygorskite. The crops were cultivated in pots consisting of a mixture of sand from Hamadan region, Iran and Florida palygorskite, irrigated with distilled water, and treated with either com.l.te or mg-free nutrient solutions. After 100 d, mg uptake by the crops was measured. Clay-sized particles in each pot were also separated from the sand and were analyzed through X-ray diffraction （XRD）. The X-ray pattern of the particles was compared with that of the pure palygorskite particles （before cultivation）. The results showed that palygorskite could provide sufficient mg for the growth of wheat in the pots supplied with mg-free nutrient solution. In spite of the magnesium uptake by both plants from the palygorskite structure, no detectable peaks indicating the transformation of pmygorskite were recognized by XRD. A decrease of 1.05 nm in peak intensity was more obvious for the pots containing palygorskite and irrigated with mg-free nutrient solution than for the pots irrigated with com.l.te nutrient solution. Although the decrease in peak intensity was greater for oat than wheat, indicating greater palygorskite weathering by oat, mg uptake by oat was low, as evidenced by the deficiency symptoms observed.

关键词： clay minerals nutrient solution rhizosphere weathering X-ray diffraction

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Viscoelastic analysis of single-component and composite PEG and alginate hydrogels

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Acta mechanica Sinica 2014年第1期30卷 7-14页

作者： Jenna m.Shapiro michelle l.Oyen Cambridge University Engineering Department CambridgeUK Eunice Kennedy Shriver National Institute of Child Health and Human Development National Institutes of Health

Hydrogels, three-dimensional hydrophilic polymer networks, are appealing candidate materials for study- ing the cellular microenvironment as their substantial water content helps to better mimic soft tissue. However, hydrogels can lack mechanical stiffness, strength, and tough- ness. Composite hydrogel systems have been shown to improve upon mechanical properties compared to their single- component counterparts. Poly （ethylene glycol） dimethacrylate （PEGDmA） and alginate are polymers that have been used to form hydrogels for biological applications. Single- component and composite PEGDmA and alginate systems were fabricated with a range of total polymer concentrations. Bulk gels were mechanically characterized using spherical indentation testing and a viscoelastic analysis framework. An increase in shear modulus with increasing polymer con- centration was demonstrated for all systems. Alginate hydro- gels were shown to have a sm.l.er viscoelastic ratio than the PEGDmA gels, indicating more extensive relaxation over time. Composite alginate and PEGDmA hydrogels exhib- ited a combination of the mechanical properties of the con- stituents, as well as a qualitative increase in toughness. Additionally, m.l.iple hydrogel systems were produced that had sim.l.r shear moduli, but different viscoelastic behaviors. Accurate measurement of the mechanical properties of hydrogels is necessary in order to determine what parameters are key in modeling the cellular microenvironment.

关键词： Hydrogel Viscoelastic Indentation Nanoin-dentation Composite

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Experimental Investigation of micro Heat Pipes of Different Cross-Sections Having Same Hydraulic Diameter

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Journal of Therm.l.Science 2008年第3期17卷 247-252页

作者： S.l.mahmood m.A.R.Akhanda Department of mechanical and Chemical Engineering Islamic University of Technology

Effects of micro heat pipe （mHP） cross-sections and orientations on its therm.l.performance are experimentally investigated in this study. Tests are conducted using five different cross-sections （circular, semicircular, elliptical, semi-elliptical and rectangular） of micro heat pipes having same hydraulic diameter of 3 rnm placed at three different inclination angles （0°, 45°, 90°）, where water is used as the working fluid. Evaporator section of the mHP is heated by an electric heater and the condenser section is cooled by circulation of water in an annular space between condenser section and the water jacket. Temperatures at different locations of the mHP are measured using five calibrated K type thermocouples. Heat supply is varied using a voltage regulator which is measured by a precision ammeter and a voltmeter. It is found that therm.l.performance tends to deteriorate as the mHP is flattened. Thus among all cross-sections of mHP, circular one exhibits the best therm.l.performance in terms of heat flux dissipation followed by semi-elliptical, semi-circular, elliptical and rectangular cross-sections. moreover, its heat transfer capability also decreases with decreasing of its inclination angle. Finally, a correlation is developed which covers all the experimental data within ＋7%.

关键词： micro heat pipe cross-section hydraulic diameter inclination.

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Ractopamine up take by alfalfa (medicago sativa) and wheat (Triticum aestivum) from soil

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Journal of Environmental Sciences 2015年第8期27卷 86-92页

作者： Weilin l.Shelver Thomas m.DeSutter USDA-ARS Biosciences Research laboratory Department of Soil Science North Dakota State University

Ractopamine is a beta adrenergic agonist used as a growth promoter in swine, cattle and turkeys. To test whether ractopamine has the potential to accum.l.te in plants grown in contaminated soil, a greenhouse study was conducted with alfalfa（medicago sativa） and wheat（Triticum aestivum） grown in two soils having different concentrations of organic matter（1.3% and 2.1%）, amended with 0, 0.5, and 10 μg/g of ractopamine. Plant growth ranged from 2.7 to 8.8 g dry weight（dw） for alfalfa, and 8.7 to 40 g dw for wheat and was generally greater in the higher organic matter content soil. The uptake of ractopamine in plant tissues ranged from non-detectable to 897 ng/g and was strongly dependent on soil ractopamine concentration across soil and plant tissue. When adjusted to the total fortified quantities, the amount of ractopamine taken up by the plant tissue was low, 〈 0.01% for either soil.

关键词： Ractopamine Plant uptake Environment Foodsafety

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Do concentrations in eggs and liver tissue tell the same story of temporal trends of mercury in high Arctic seabirds?

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Journal of Environmental Sciences 2018年第6期30卷 65-72页

作者： mark l.m.l.ory Birgit m.Braune Biology Department Acadia University Environment and Climate Change Canada National Wildlife Research Centre Carleton University

mercury（Hg） remains a key contaminant of concern in Arctic biota, and monitoring of Hg concentrations in seabird tissues will be an effective approach to track the effects of im.l.menting the minamata Convention. We examined trends in total Hg（THg） in liver and egg tissues of two Arctic seabirds, thick-billed murres（Uria lomvia） and northern fulmars（Fulmarus glacialis）, between 1976 and 2013 to assess whether both tissues showed sim.l.r patterns of Hg change. Hepatic THg was consistently higher than egg THg, and both species had sim.l.r egg THg concentrations, but fulmars had higher hepatic THg than *** THg concentrations showed more relative variation through time than *** suggest that egg THg better reflects exposure of birds to THg in local, Arctic prey,whereas liver THg may incorporate longer term, year-round THg exposure. Additional analysis of THg distribution in Arctic seabirds post-laying would help inform interpretation of long-term trends.

关键词： Canada Fulmarus glacialis Northern fulmar Thick-billed murre Uria lomvia

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Spent coffee grounds as a renewable source of energy: An analysis of bulk powder flowability

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Particuology 2019年第2期17卷 92-100页

作者： l. massaro Sousa m.C. Ferreira Drying Center for Pastes Suspensions and Seeds. Chemical Engineering Department Federal University of Sao Carlos. P.O. Box 676 13565-905 Sao Carlos Brazil

The main use for spent coffee grounds (SCG) produced in the soluble coffee industry is therm.l.energy generation in the industry itself. The SCG are processed using operations that are strongly dependent on powder flow behavior. In this study, we evaluated two classical flowability in dices of non-consolidated SCG powders: the angle of repose (AoR), and the Hausner ratio (HR). The influences of the mean particle diameter, particle size distribution (PSD), and water content on the AoR and HR values of SCG were analyzed for powders with a mean particle size range of 225-550 μm. For powders with a mean particle size close to 350 μm and for mixtures containing more than 40% fine particles, the HR (>1.35) and AoR (>45 °) values were characteristic of poor flowability. The AoR was sensitive to the powder PSD, and powders with sim.l.r mean particle sizes had higher AoR values when the PSD was larger. For powders w让h water contents up to 50%, the flowability indices were not greatly affected by the water content. A modified linear-mixture packing model was used to predict the packed bed void fractions for binary and ternary mixtures of the three base powders. The model was used to construct a ternary diagram to estimate the HR values of the mixtures. An equation was fitted to correlate HR and AoR. The proposed diagram and the equation provide insight into flow behavior and could be used for process design of industrial plants that handle SCG.

关键词： Spent coffee ground Biomass Flowability Hausner ratio Angle of repose

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DNS in evolution of vorticity and sign relationship in wake transition of a circular cylinder:(pure)mode A

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Acta mechanica Sinica 2019年第6期35卷 1131-1149页

作者： l.m.l.n Z.R.Tan Key laboratory for mechanics in Fluid Solid Coupling Systems Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Navigation Wuhan University of TechnologyWuhan 430063China Hubei Key laboratory of Inland Shipping Technology Wuhan University of TechnologyWuhan 430063China

In the present paper,the spatio-temporal evolution of vorticity in the first wake instability,i.e.,(pure)mode A,is investigated in order to understand the wake vortex dynamics and sign relationships among vorticity *** numerical sim.l.tion(DNS)for the flow past a circular cylinder is performed,typically at a Reynolds number of 200,in the three-dimensional(3-D)wake *** to characteristics of time histories of fluid forces,three different stages are identified as the computational transition,the initial stage and fully developed *** the second initial stage,the original two-dimensional spanwise vortices become obviously three-dimensional associated with the streamwise or vertical vorticity intensified up to about *** a matter of fact,these additional vorticities,caused by the intrinsic 3-D instability,are already generated firstly on cylinder surfaces early in the computational transition,indicating that the three-dimensionality appeared early near the *** evolution of additional components of vorticity with features the same as mode A shows that(pure)mode A can be already formed in the late computational *** careful analysis of the vorticity field on the front surface,in the shear layers and near wake at typical times,two sign laws are *** illustrate intrinsic relationships among three vorticity components,irrelevant to the wavelength or Fourier mode and Reynolds number in(pure)mode *** importantly,the origin of streamwise vortices is found and explained by a new physical mechanism based on the theory of vortex-induced *** a result,the whole process of formation and shedding vortices with these vorticities is firstly and com.l.tely *** characteristics are presented in detail.

关键词： Wake transition Circular cylinder Vorticity mode A Sign law

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作为历史资料的英雄史诗《江格尔》

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民族文学研究 1991年第1期9卷 91-95页

作者： m.l.乞齐科夫阿拉腾奥其尔

史诗《江格尔》是否具有历史真实性这一问题早已成为研究卡尔梅克英雄史诗的蒙古学家们所关注的中心问题。在这一问题上,历来就有各种不同的见解。臂如:著名的卡尔梅克学家A.A.波布罗甫尼科夫就不认为史诗《江格尔》有什么历史性可言。1... 详细信息

史诗《江格尔》是否具有历史真实性这一问题早已成为研究卡尔梅克英雄史诗的蒙古学家们所关注的中心问题。在这一问题上,历来就有各种不同的见解。臂如:著名的卡尔梅克学家A.A.波布罗甫尼科夫就不认为史诗《江格尔》有什么历史性可言。1854年,他写道:“……在叙事部分没有任何历史的痕迹,这是不言而喻的”。但大多数研究者都不同意他的这一观点。就这一问题,S.A.科津、V.A.扎克鲁特金、B.K.帕什科夫、G.I.米哈依洛夫以及其他一些学者都提出了非常明确的见解。当然,如果说波布罗甫尼科夫把英雄史诗仅限定为“纯幻想”的东西,那么,这则是他的折衷主义方法论的结果。

关键词：卡尔梅克人卫拉特人准噶尔蒙古学历史时期氏族部落历史事实英雄史诗汗国统治者

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mechanical stress and deformation analyses of pressurized cylindrical shells based on a higher-order modeling

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Defence Technology（防务技术） 2023年第2期20卷 24-33页

作者： S.mannani l.Collini m.Arefi Department of Solid mechanic Faculty of Mechanical EngineeringUniversity of KashanKashan87317-51167Iran Department of Engineering and Architecture University of ParmaParco Area Delle Scienze 181/A43124ParmaItaly

In this research,mechanical stress,static strain and deformation analyses of a cylindrical pressure vessel subjected to mechanical loads are *** kinematic relations are developed based on higherorder sinusoidal shear deformation *** stretching form.l.tion is accounted for more accurate *** total transverse deflection is divided into bending,shear and thickness stretching parts in which the third term is responsible for change of deflection along the thickness *** axisymmetric form.l.tions are derived through principle of virtual work.A parametric study is presented to investigate variation of stress and strain components along the thickness and longitudinal *** explore effect of thickness stretching model on the static results,a comparison between the present results with the available results of literature is *** an important output,effect of micro-scale parameter is studied on the static stress and strain distribution.

关键词： Principle of virtual work Thickness-stretched and shear deformable model Stress and strain analyses Cylindrical pressure vessel

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No benefit of flat head positioning in early moderate-severe acute ischaemic stroke: a HeadPoST study subgroup analysis

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Stroke & Vascular Neurology 2020年第4期5卷 406-409页

作者： Alejandro m Brunser menglu Ouyang Hisatomi Arima Pablo m.l.vados Thompson Robinson Paula munoz-Venturelli Veronica V Olavarria laurent Billot marre l Hackett lili Song Sandy middleton Octavio Pontes-Neto Tsong-Hai lee Caroline Watkins Craig S Anderson Department of General Emergency Clinica Alemana de SantiagoClinica Alemana Universidad del DesarrolloSantiagoChile Department of Neurology and Psychiatry Clinica Alemana de SantiagoFaculty of MedicineClinica Alemana Universidad del DesarrolloSantiagoChile The George Institute for Global Health University of New South WalesSidneyNew South WalesAustralia The George Institute in China Peking University Health Science CenterBeijingChina Department of Preventive medicine and Public Health Fukuoka UniversityFukuokaJapan Department of Cardiovascular Sciences and NIHR leicester Biomedical Research Centre University of LeicesterLeicesterUnited Kingdom Faculty of Health and Wellbeing University of Central LancashirePrestonLancashireUnited Kingdom Nursing Research Institute St Vincent's Health Network Sydney AustraliaAustralian Catholic UniversitySydneyNew South WalesAustralia Stroke Service-Neurology Division Department of Neuroscience and Behavioral SciencesRibeirao Preto Medical SchoolUniversity of Sao PauloSao PauloBrazil Stroke Center and Department of Neurology Linkou Chang Gung Memorial Hospital and College of MedicineChang Gung UniversityTaoyuanTaiwan

background Although the Head Positioning in acute Stroke Trial(HeadPoST)showed no effect of the flat head position(FP;vs sitting up head position(SUP))on functional outcome,we hypothesised that it could still offer benefits if commenced early in those with acute ischaemic stroke(AIS)of at least moderate *** Subgroup analysis of HeadPoST in participants with National Institutes of Health Stroke Scale(NIHSS)scores≥7,≥10 and≥14,randomised to FP or SUPl outcomes defined by a shift in scores on the modified Rankin scale(mRS)and death/disability(mRS scores 3-6),and any cardiovascular serious adverse *** regression analyses were undertaken adjusted for study design and baseline risk *** There was no significant differential treatment effect in patient subgroups defined by increasing baseline NIHSS scores:adjusted OR and 95%CI for ordinal shift and binary(3-6)mRS scores:for NIHSS≥7(n=867)0.92(0.67 to 1.25)and 0.74(0.52 to 1.04);NIHSS≥10(n=606)0.80(0.58 to 1.10)and 0.77(0.49 to 1.19);NIHSS≥14(n=378)0.82(0.54 to 1.24)and 1.22(0.69 to 2.14).Conclusions Early FP had no significant effect in patients with moderate-severe AIS.

关键词： acute analysis effect

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