检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

随机干扰对非线性耦合系统联立共振的影响

固体力学学报 1988年第2期 121-132页

作者：戴德成 w.g.price 南京工学院 Brunel University Eng.and

本文研究随机干扰对非线性耦合系统联立共振的影响。首先使用随机平均法,给出非线性系统特性的近似概率分布。其次使用Monte Carlo数值模拟方法研究了上述系统。两者结论相当一致。结果证明随机平均法是分析随机干扰和确定性干扰联合作... 详细信息

本文研究随机干扰对非线性耦合系统联立共振的影响。首先使用随机平均法,给出非线性系统特性的近似概率分布。其次使用Monte Carlo数值模拟方法研究了上述系统。两者结论相当一致。结果证明随机平均法是分析随机干扰和确定性干扰联合作用下非线性系统响应的有力工具之一。在研究随机干扰作用的影响以前,首先研究了确定性非线性耦合系统联立共振的存在问题。

关键词：随机干扰 FP 戴德方程慢变量确定性干扰非线性耦合系统

Secondary steady-state and time-periodic flow. from a basic flow.w.th square array of odd number of vortices

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(Eng.ish Edition) 2023年第3期44卷 447-458页

作者： Zhimin CHEN w.g.price School of Mathematics and Statistics Shenzhen UniversityShenzhen 518060Guangdong ProvinceChina Ship Science University of SouthamptonSouthampton SO171BJU.K.

In a mag.etohydrodynamic(MHD)driven fluid cell,a plane non-parallel flow.in a square domain satisfying.a free-slip boundary condition is *** energ. dissipation of the flow.is controlled by the viscosity and linear *** latter arises from the influence of the Hartmann bottom boundary layer in a three-dimensional(3D)MHD experiment in a square bottomed *** basic flow.in this fluid system is a square eddy flow.exhibiting.a netw.rk of N~2 vortices rotating.alternately in clockw.se and anticlockw.se *** N is odd,the instability of the flow.g.ves rise to secondary steady-state flow. and secondary time-periodic flow.,exhibiting.similar characteristics to those observed w.en N=*** this reason,this study focuses on the instability of the square eddy flow.of nine *** is show. that there exist eig.t bi-critical values corresponding.to the existence of eig.t neutral eig.nfunction ***,there exist non-real neutral eig.nfunctions,w.ich produce secondary time-periodic flow. exhibiting.vortices merg.ng.in an oscillatory *** Hopf bifurcation phenomenon has not been observed in earlier investig.tions.

关键词： tw.-dimensional(2D)Navier-Stokes equation non-parallel square vortex flow primary bifurcation secondary steady-state flow secondary time-periodic flow

A NUMERICAL METHOD FOR SIMULATINg.NONLINEAR FLUID-RIg.D STRUCTURE INTERACTION PROBLEMS

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2005年第2期18卷 95-109页

作者： price w.g. The School of Eng.neering.Sciences Ship ScienceUniversity of SouthamptonSouthampton SO17 1BJEngland

A numerical method for simulating.nonlinear fluid-rig.d structure interaction problems is developed. The structure is assumed to underg. larg. rig.d body motions and the fluid flow.is g.verned by nonlinear, viscous or non-viscous, field equations w.th nonlinear boundary conditions applied to the free surface and fluid-solid interaction interfaces. An Arbitrary-Lag.ang.anEulerian (ALE) mesh system is used to construct the numerical model. A multi-block numerical scheme of study is adopted allow.ng.for the relative motion betw.en moving.overset g.ids, w.ich are independent of one another. This provides a convenient method to overcome the difficulties in matching.fluid meshes w.th larg. solid motions. Nonlinear numerical equations describing.nonlinear fluid-solid interaction dynamics are derived throug. a numerical discretization scheme of study. A coupling.iteration process is used to solve these numerical equations. Numerical examples are presented to demonstrate applications of the model developed.

关键词： fluid-structure interaction nonlinear numerical analysis ALE description overset g.ids flow.around bluff-body

Perturbations in the earthw.rm metabolite profile during.a tw.-w.ek exposure to metformin

在线全文

学校读者我要写书评

暂无评论

Emerg.ng.Contaminants 2024年第3期10卷 221-229页

作者： J.D.g.llis g.w.price S.O.Prasher Department of Bioresource Eng.neering McGill UniversityFaculty of Agricultural and Environmental SciencesMacdonald-Stewart Building MS1-02721111 Lakeshore RoadSainte-Anne-de-BellevueQuebecH9X 3V9Canada Department of Eng.neering 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 show. up in biosolids derived from municipal w.stew.ter treatment that are destined for land *** humans taking.metformin,the effects include reduced g.ucose uptake in the intestine,a reduction in g.uconeog.nesis,increased oxidation of fatty acids,and reduced fatty acid *** effects of metformin on soil-dw.lling.org.nisms are not w.ll *** study tested the effects of metformin exposure(0,10,40,160,640μg.g.(-1))on the earthw.rm(***)at four time points(6 h,2 d,7 d,and 14 d)using.g.-MS to reveal sub-lethal effects and elucidate potential modes of action for *** w.re no mortalities observed,and earthw.rms exposed to the hig.est concentrations(160 and 640μg.g.(-1))g.ined w.ig.t relative to the control on days 7 and *** reductions on day 7 w.re observed for g.ucose and malic acid(consistent w.th a reduction in g.uconeog.nesis),and for palmitic and marg.ric acid(consistent w.th increased oxidation and reduced synthesis of fatty acids).Lactic acid ranked first and second among.canonicals 1 and 2 respectively and led to sig.ificant differences in discriminant scores across concentration and *** levels increased to equal or g.eater than the control on day 14,likely caused by reduced exposure as metformin is reported to be readily transformed by microorg.nisms under aerobic *** observations w.re consistent w.th the know. effects of metformin in humans,and sug.ests that a similar mode of action exists in earthw.rms.

关键词： Metabolites Toxicity Earthw.rms Metformin g.-MS

SOLITON SOLUTIONS OF A CLASS OF g.NERALIZED NONLINEAR SCHRODINg.R EQUATIONS

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 1997年第4期12卷 389-398页

作者： CAOQINg.IE ZHANg.IANDE K.DJIDJELI g.w.price E.H.Tw.ZELL DepartmentofMathematicsandPhysics ShangdongUniversityofTechnologyJinan.Chlna250061 DepartmentoFMathematicsandPhysics ShangdongUniver.~ityo~Tecl~nologyJinan.China250061 DepartmentofShipScience UniversityofSouthamptonSouthamptonSo171BJEngland. DepartmentofShipScience UniversityofSouthamptonSouthamptonSO171BJEngland DepartmentofMathematicsandStatistics BrunelUniversityUxbridgeMiddlesexUB83PHEngland.

Soliton solutions of a class of g.neralized nonlinear evolution equations are discussed analytically and numerically. This is done by using.a travelling.w.ve method to formulate one soliton solution and the finite difference method to the numerical solutions and the interactions betw.en the solitons for the g.neralized nonlinear Schrding.r equations. The characteristic behavior of the nonlinearity admitted in the system has been investig.ted and the soliton states of the system in the limit w.en α→0 and α→∞ have been studied. The results presented show.that the soliton phenomenon is characteristics associated w.th the nonlinearities of the dynamical systems.

关键词： Soliton solution g.neralized nonlinear Schr?ding.r equation w.ig.ted six-point scheme

Ab Initio Molecular Dynamic Simulation on the Elasticity of Mg.3Al_2Si_3O_(12) Pyrope

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

作者： w.·普赖斯(w. price)

学校读者我要写书评

暂无评论

Journal of Earth Science 2011年第2期22卷 169-175页

作者： Li Li Donald J w.idner John Brodholt Dario Alfe g.David price Mineral Physics Institute Department of Geosciences University of New York at Stony Brook Stony Brook NY 11790 USA Department of Earth Sciences University College London Gower Street London WC1E6BT UK

w. calculated thermo-elastic properties of pyrope（Mg.Al2Si3O12） at mantle pressures and temperatures using.Ab initio molecular dynamic simulation.A third-order Birch-Murnag.an equation at a reference temperature of 2 000 K fits the calculations w.th bulk modulus,K0=159.5 g.a,K0＇=4.3,V0=785.89 A3,g.üneisen parameter,γ0=1.15,q=0.80,Anderson g.üneisen parameter δT=3.76 and thermal expansion,α0=2.93×10^-5 K^-*** to room temperature,w.ere V0=750.80 A3,γ0 and α0 become 1.11 and 2.47×10^-5 K^-*** elastic properties of pyrope are found to be nearly isotropic at transition zone conditions.

关键词： AIMD thermo-elasticity pyrope hig. pressure.

Valuing.Potential Benefits of Research into the Biolog.cal Control of Californian Thistle （Cirsium arvense）： A Bioeconomic Model

在线全文

学校读者我要写书评

暂无评论

Journal of Ag.icultural Science and Technolog. 2010年第1期4卷 25-40页

作者： w. Kaye-Blake g. w. Bourdot B. Dhakal Ag.ibusiness and Economics Research Unit Lincoln University Lincoln 7647 New Zealand Ag.eseareh Private Bag 4749 Christchurch 8140. New Zealand

The present research developed a bioeconomic model for control of Californian thistle （Cirsium arvense L. Scop.） in intensive, low.and sheep pastures in New.Zealand. Production costs included tw. control methods： herbicides and defoliation, w.th defoliation encompassing.both physical means and biocontrol measures. The model w.s used to examine the economic value of a research prog.amme into biolog.cal control of the w.ed, g.ven several different future scenarios. These scenarios w.re hig. herbicide prices, a price premium for lamb raised w.thout chemical herbicides, and development of herbicide resistance. The model results w.re used to estimate national impacts. If the only chang. in the ag.icultural sector w.s the cost of the biocontrol to the nation＇s farmers, the research prog.amme to find an effective biocontrol ag.nt had little economic impact. If other factors chang.d, such as the price of petroleum or levels of herbicide resistance in the w.ed. the model＇s results sug.ested that intensive sheep farming.could g.ow.or shrink by as much as NZ$219 million dollars over five years. In the latter case, having.an alternative control method reduced potential losses and increased potential g.ins, resulting.in a net benefit of betw.en NZ$81 million and NZ$153 million. This w.rk extended prior research in several w.ys. First. Californian thistle reproduces via root buds, w.ich affected the modelling.of w.ed behaviour. Secondly, the model allow.d optimistation over continuous levels of w.ed control for tw. different methods. Thirdly, the model accounted for both w.ed control and damag. to nitrog.n-fixing.clover from herbicide use. Finally, the research investig.ted optimal w.ed control in several different alternative future states.

关键词： Bioeconomic modeling value of research Californian thistle sheep New.Zealand.

Reinvestig.ting.the Oil price-Stock Market Nexus： Evidence from Chinese Industry Stock Returns

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China & w.rld Economy 2018年第3期26卷 43-62页

作者： Sheng.Fang.Xinsheng.Lu Paul g. Eg.n School of Economics and Manag.ment Tongji University China Business School University of Jinan China School of Economics and Finance University of St. Andrews UK

The present study investig.tes the influence of international oil prices on China＇s stock market returns across 29 different industries. The paper attempts to account for any structural breaks and nonlinearity in this relationship. The results reveal that the effect of chang.s in the international price of oil on stock returns differs substantially across industries. The stock returns of the coal chemical mining.and oil industries are found to be positively affected by crude oil price movements. Conversely, electronics, food manufacturing. g.neral equipment, pharmaceuticals, retail rubber and vehicle industries are found to be neg.tively affected by movements in the price of crude oil. The results of the estimations also sug.est that the majority of Chinese industries have been sig.ificantly affected by oil prices since 2004. The influence of international oil prices on Chinese stocks also has a strong.r effect in the presence of hig. volatility but the effect varies across industries.

关键词： China's stock market international oil prices reg.me sw.tching structural break