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perturbations in the earthworm metabolite p.o.ile during a two-week exposure to metformin

Emerging Contaminants 2024年第3期10卷 221-229页

作者： J.D.Gillis G.W.price S.o.prasher Department of Bioresource Engineering McGill UniversityFaculty of Agricultural and Environmental SciencesMacdonald-Stewart Building MS1-02721111 Lakeshore RoadSainte-Anne-de-BellevueQuebecH9X 3V9Canada Department of Engineering Dalhousie UniversityFaculty of Agriculture39 Cox RoadPO Box 550TruroNova ScotiaB2N 5E3Canada

Metformin is among the most prescribed pharmaceuticals in many countries,and as a result has shown up in biosolids derived from municipal wastewater treatment that are destined for land *** humans taking metformin,the effects include reduced glucose uptake in the intestine,a reduction in gluconeogenesis,increased oxidation of fatty acids,and reduced fatty acid *** effects of metformin on soil-dwelling organisms are not well *** study tested the effects of metformin exposure(0,10,40,160,640μg g^(-1))on the earthworm(***)at four time points(6 h,2 d,7 d,and 14 d)using GC-MS to reveal sub-lethal effects and elucidate potential modes of action for *** were no mortalities observed,and earthworms exposed to the highest concentrations(160 and 640μg g^(-1))gained weight relative to the control on days 7 and *** reductions on day 7 were observed for glucose and malic acid(consistent with a reduction in gluconeogenesis),and for palmitic and margaric acid(consistent with increased oxidation and reduced synthesis of fatty acids).Lactic acid ranked first and second among canonicals 1 and 2 respectively and led to significant differences in discriminant scores across concentration and *** levels increased to equal or greater than the control on day 14,likely caused by reduced exposure as metformin is reported to be readily transformed by microorganisms under aerobic *** observations were consistent with the known effects of metformin in humans,and suggests that a similar mode of action exists in earthworms.

关键词： Metabolites Toxicity Earthworms Metformin GC-MS

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X-ray Crystallinity Studies of palladium polyacrylate

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Journal of Materials Science & Technology 1995年第4期11卷 310-312页

作者： R.Hussain and D.Mohammad (pakistan Institute of Nuclear Science and Technology, p.o.box 1356, Islamabad, pakistan) pAKISTAN INST NUCL SCI & TECHNoL ISLAMABADPAKISTAN

Free radical polymerized palladium polyacrylate was characterized by X-ray diffraction. Various parameters including mean crystallite size, interchain separation and radius of gyration have been calculated and discussed with respect to the concentration of pd in the polymeric salt. The results show that polymer is predominantly amorp.o.s in nature.

关键词： UK X-ray Crystallinity Studies of palladium polyacrylate John

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Dynamic behaviors of cavitation bubble for the steady cavitating flow

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Journal of Thermal Science 2009年第4期18卷 338-344页

作者： Jun CAI,Xiulan HUAI and Xunfeng LIInstitute of Engineering Thermophysics,Chinese Academy of Sciences,p.o.box 2706,Beijing 100190,China p.o.essor Institute of Engineering Thermophysics Chinese Academy of Sciences P.O.Box 2706 Beijing 100190 China

In this paper, by introducing the flow velocity item into the classical Rayleigh-plesset dynamic equation, a newequation, which does not involve the time term and can describe the motion of cavitation bubble in the steadycavitating flow, has been obtained. By solving the new motion equation using Runge-Kutta fourth order methodwith adaptive step size control, the dynamic behaviors of cavitation bubble driven by the varying pressure fielddownstream of a venturi cavitation reactor are numerically simulated. The effects of liquid temperature (correspondingto the saturated vapor pressure of liquid), cavitation number and inlet pressure of venturi on radial motionof bubble and pressure pulse due to the radial motion are analyzed and discussed in detail. Some dynamicbehaviors of bubble different from those in previous papers are displayed. In addition, the internal relationshipbetween bubble dynamics and p.o.ess intensification is also discussed. The simulation results reported in thiswork reveal the variation laws of cavitation intensity with the flow conditions of liquid, and will lay a foundationfor the practical application of hydrodynamic cavitation technology.

关键词： cavitation bubble bubble dynamics hydrodynamic cavitation cavitating flow p.o.ess intensification

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Distribution　of　Exchangeable　Calcium，Magnesium　and　potassium　as　Affected　by　Fertilizer　Application　to　Red　Soil

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pedosphere 1995年第4期5卷 343-348页

作者： SHEN REN-FANG and ZHAo QI-GUo(Laboratocy of Material Cycling in pedosphere, Institute of Soil Science, Academia Sintca, p.o. box 821,Nanjing 210008)(China)

A leaching experiment was carried out with repacked soil columns in laboratory to stndy the leachingp.o.ess of a red soil derived from sandstone as affected by warions fertilization practices. The treatments wereCK (as a control), CaCo_3, CaSo_4, MgCo_3, Ca(H_2po_4)_2, Urea, KCl, Mnltiple (a mixture of the above-mentioned fertilizers), and KNo_3. The fertilizers were added to the bare surface of the soil columns, andthen the columns were leached with 120 mL deionized water daily through peristaltic pumps over a periodof 92 days. At the end of leaching p.o.ess, soils were sampled from different depths of the soil p.o.iles, i.e.,0-5 cm, 5-10 cm, 10-20 cm, 20-40 cm, and 40-60 cm. The results showed when applying Ca, Mg, andK to the bare surface of the soil columns, exchangeable Ca￣(2+), Mg￣(2+), and K￣+ in the upper layer of thesoil p.o.ile increased correspondingly, with an extent depending mainly on the application rates of Ca, Mg,and K and showing a downward trend. CaCo_3, CaSo_4, MgCo_3, and Ca(H_2po_4)_2 treatments had scarcelyany effect on movement of exchangeable K￣+, while CaCo_3, and CaSo_4 treatments significantly p.o.otedthe downward movement of exchangeable Mg￣(2+) although these two treatments had no obvious effect onleaching losses of Mg. The fact that under Urea treatment, exchangeable Ca￣(2+) and Mg￣(2+) were higheras compared to CK treatment showed urea could prevent leaching of exchangeable Ca￣(2+) and Mg￣(2+). Theobvious downward movement of exchangeable Ca￣(2+) and Mg￣(2+) was noticed in KCl treatment. In Multipletreatment, the downward movement of exchangeable Ca￣(2+) and Mg￣(2+) was evident, while that of K￣+ was lessevident. Application of KNo_3 strongly p.o.oted the downward movement of exchangeable Ca￣(2+) and Mg￣(2+)in the soil p.o.ile.

关键词： distribution of exchangeable Ca￣(2+) Mg￣(2+) and k￣+ fertilization leaching red soil

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A Class of Explicit parallel Multistep Runge-Kutta Methods

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Journal of Systems Engineering and Electronics 1993年第4期4卷 64-72页

作者： Xie Yajun and Liu DeguiBeijing Institute of Computer Application and Simulation Technology p.o.box. 3929, Beijing 100854, China Beijing Institute of Computer Application and Simulation Technology p.o. box. 3929 Beijing 100854 China

In this paper, a rather general class of explicit parallel multistep Runge-Kutta methods is constructed for solving initial value p.o.lem of ordinary differential equations. Also, the corresponding convergence and stability are analysed. Several parallel computational formulae are given. The numerical experiments, including accuracy, speedup, and efficiency tests show that the methods are efficient.

关键词： Runge-Kutta method Initial value p.o.lem.

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Effect of Specific Adsorption of Ions on Electrokinetic p.o.erties of Variable Charge Soils

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pedosphere 1991年第1期1卷 41-50页

作者： ZHANG HoNG and ZHANG XIAo-NIANInstitute of Soil Science, Academia Sinica, and Laboratory of Material Cycling in pedosphere, Academia Sinica, p.o. box 821. Nanjing ( China) InstituteofSoilScience AcademiaSinicaandLaboratoryofMaterialCyclinginPedosphereAcademiaSinicaP.O.B

Studies were carried out by using electrop.o.etic method on the effects of the specific adsorption of the anions,such as So4^2-,po4^3-,and F^- ions,the cations,such as Ca^2+,Mn^2+,Zn^2+,and Cu^2+,ions,and the anions and cations coexisting,such as Zn^2+ and So4^2= ions,on electrokinetic p.o.erties of the red soils as typical variable charge soils in China concerning variation in the specific ion species and concentrations,with an emphasis on the interaction between soil colloid surfaces and the ions in soil *** results showed that the adsorption of specific ions led to a very p.o.ounced decrease in zeta potentials of the soil colloids and a shift of the IEps to lower values for specific anions,and an obvious increase in zeta potentials of the soil colloids and a shift of the IEps to higher values for specific *** circumstances of the specific anions and cations coexisting,for instance,Zn^2+ and So4^2- ions,the zeta potentials changed with values higher than the value for So4^2- alone and lower than that for Zn^2+ alone,and the IEp was between that for Zn^2+ and that for So4^2-.The adsorption of Zn^2+ and Cu^2+ ions resulted in a reversal of the zeta potentials,and appearance of two IEps for Zn^2+ and no IEp for Cu^2+,exhibiting interesting special effects of these kinds of metal *** higher the concentrations of the ions,the greater the change of the electrokinetic p.o.erties.

关键词： Electrokinetic p.o.erties specific adsorption variable charge soils

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Grid dispersion in generating finite-differences synthetic seismograms

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Acta Seismologica Sinica(English Edition) 1994年第3期7卷 397-407页

作者： Abdolrahim Javaherian (Institute of Geophysics, the University of Tehran, p. o. box 14155-4666 Tehran, Islamic Republic of Iran) 1. Institute of Geophysics the University of Tehran P. O. Box 14155-4666 Tehran Islamic Republic of Iran

In order to obtain a finite-difference synthetic seismogram, the finite earth model must be subdivided into *** the cell size becomes too large in comparison with wavelength of the source signal, waves disperse with increasing traveltime. This phenomenon is known as grid dispersion. The grid dispersion p.o.uces a variation of velocity with different frequencies; that is the higher signal frequencies travel more slowly than the lower signal frequencies. Consequently, substantial tailing of the signal arises with increasing traveltime. This may happpen if: (1) the grid spacing is large; (2) the sampling rate is large; or (3) the source wavelength is too short compared with grid size. In other words, an important parameter in generating finite-difference synthetic seismograms is the number of grid points per wavelength of the source signal. In this paper, it is shown that the frequency of a source function has great effects on grid dispersion when p-Sv coupled waves p.o.agate through elastic models by finite-differences. The two-dimensional elastic models considered in this paper consist of : (1) a normal fault, and (2) a layer over a half-space. This study verifies that, when generating finite-difference synthetic seismograms, the grid dispersion will be reduced to a satisfactory level if the grid points per wavelength at the half-power frequency of the source signal for the lowest velocity of the medium exceeds ten.

关键词： grid dispersion finite differencess synthetic seismograms

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Tensor Theory of High Energy Electron Diffraction and Its Applications in Crystalography

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电子显微学报 1997年第4期 157-160页

作者： L. M.peng (Beijing Laboratory of Electron Microscopy, Chinese Academy of Sciences, p.o. box 2724, Beijing 100080, p.R. China)

ＴｅｎｓｏｒＴｈｅｏｒｙｏｆＨｉｇｈＥｎｅｒｇｙＥｌｅｃｔｒｏｎＤｉｆｆｒａｃｔｉｏｎａｎｄＩｔｓＡｐｐｌｉｃａｔｉｏｎｓｉｎＣｒｙｓｔａｌｏｇｒａｐｈｙＬ．Ｍ．Ｐｅｎｇ（ＢｅｉｊｉｎｇＬａｂｏｒａｔｏｒｙｏｆＥｌ... 详细信息

ＴｅｎｓｏｒＴｈｅｏｒｙｏｆＨｉｇｈＥｎｅｒｇｙＥｌｅｃｔｒｏｎＤｉｆｆｒａｃｔｉｏｎａｎｄＩｔｓＡｐｐｌｉｃａｔｉｏｎｓｉｎＣｒｙｓｔａｌｏｇｒａｐｈｙＬ．Ｍ．Ｐｅｎｇ（ＢｅｉｊｉｎｇＬａｂｏｒａｔｏｒｙｏｆＥｌｅｃｔｒｏｎＭｉｃｒｏｓｃｏｐｙ，...

关键词： Its and Diffraction Crystalography Applications

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Research Activities on Space Electronics in CAST

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Journal of Systems Engineering and Electronics 1993年第3期4卷 2-6页

作者： Chen Shiping and Wang YifeiXi’an Institute of Space Radio Technology, CAST MAS, p.o. box 165. Xi’an 710000, China Xi'an Institute of Space Radio Technology CAST MAS P.O. Box 165. Xi'an 710000 China

This paper gives a brief review of the research activities on space electronics done in Chinese Academy of Space Technology (CAST), especially in Xi'an Institute of Space Radio Technology (XISRT). XISRT undertakes the development and manufacturing of space borne electronic equipment and their relevant ground TT&C in CAST. This paper deals with satellite communication and remote sensing.

关键词： Research activities Space electronics CAST Satellite communication Remote sensing.

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A THEoRETICAL INVESTIGATIoN oF BUBBLE ELECTRop.o.ESIS

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中国有色金属学会会刊：英文版 1996年第3期6卷 10-15页

作者： Xu Jirun Kelsall G H (p.o.box 139, Northeastern University, Shenyang 110006 Imperial College of Science and Technology, London, England) Northeastern University P.O. Box 139 Shenyang 110006 China Imperial College of Science and Technology London United Kingdom

ＡＴＨＥＯＲＥＴＩＣＡＬＩＮＶＥＳＴＩＧＡＴＩＯＮＯＦＢＵＢＢＬＥＥＬＥＣＴＲＯＰＨＯＲＥＳＩＳ￥ＸｕＪｉｒｕｎ；ＫｅｌｓａｌｌＧＨ（Ｐ．Ｏ．Ｂｏｘ１３９，ＮｏｒｔｈｅａｓｔｅｒｎＵｎｉｖｅｒｓｉｔｙ，Ｓｈｅｎｙａｎ... 详细信息

ＡＴＨＥＯＲＥＴＩＣＡＬＩＮＶＥＳＴＩＧＡＴＩＯＮＯＦＢＵＢＢＬＥＥＬＥＣＴＲＯＰＨＯＲＥＳＩＳ￥ＸｕＪｉｒｕｎ；ＫｅｌｓａｌｌＧＨ（Ｐ．Ｏ．Ｂｏｘ１３９，ＮｏｒｔｈｅａｓｔｅｒｎＵｎｉｖｅｒｓｉｔｙ，Ｓｈｅｎｙａｎｇ１１０００６ＩｍｐｅｒｉａｌＣｏ...

关键词： bubble fluid recirculation interface potential electrop.o.etic mobility

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