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STUDY ON ERGONOMICS AND ITS USE IN THE HARVESTING SYSTEM

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Journal of Northeast Forestry university 1992年第2期3卷 78-83页

作者： Xu Qichun Wang Weijie Northeast Forestry university Lan Fcngchong jilin university of Technology Northeast Forestry university China jilin university of Technology China

This paper describes the researching aim and content of *** prob-lems existing in modern harvesting system,such as machinery availability,cabin design,occupational accident,noise and vibration are discussed from the v... 详细信息

关键词： Ergonomics Felling and transport system Application

In situ infrared investigation of alkylation reaction of dianionic triruthenium ketenylidene cluster on magnesium oxide with methyl iodide

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Chinese Journal of Chemistry 1993年第6期11卷 517-523页

作者： XIAO, Feng-Shou, Department of Chemistry, jilin university, Changchun 130023 Department of Chemistry Jilin University Changchun 130023

The reaction between [Ru_3(CO)_9(CCO)]^(2-) supported on magnesium oxide and alky- lating agent CH_3I was investigated in an attempt to understand its reactivity and mechanism by using FT-IR technique. The IR spectra show that [Ru_3(CO)_9(CCO)]^(2-)/MgO reacts with CH_3I to produce [Ru_3(CO)_9CC(O)CH_3]-/MgO, which exhibits bands at 2960, 2022, 1988, 1638, 1460 and 1350 cm^(-1). The absorption at 2960, 1460 and 1350 cm^(-1) are attributed to -CH_3 group, while bands at 2022, 1988 and 1952 cm^(-1) are assigned to the terminal CO groups attached to ruthenium. The band at 1638 cm^(-1) was assigned to acyl carbonyl. Isotopes labeled compounds CD3I, ^(13)CO and [Ru_3(CO)_9(*C*CO)]^(2-) were used in investigation. The results demonstrate that β-carbon of CCO ligand is attacked by CH_3^+ species and produces [Ru_3(CO)_9CC(O)CH_3]-/MgO.

关键词： Ru CCO

Effect of Nb on the Interfacial Wettability in Al_2O_3/Medium Mn Steel

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Journal of Materials Science & Technology 2003年第6期19卷 625-627页

作者： Sirong YU, Yaohui LIU and Zhenming HECollege of Materials Science and Engineering, jilin university, Changchun 130025, China Coll. of Mat. Sci. and Eng. Jilin Univ. Changchun 130025 China

To develop medium Mn steel (MMS) matrix composites reinforced by AI2O3 particles, the effect of Nb on the interfacial wettability of AI2O3/MMS and its mechanism were investigated in this paper. The results show that the wetting angle of the specimens with different Nb contents are bigger than that of the specimen without Nb at the first stage, and then decreases with time at 1450℃. At certain time, the wetting angle is lower than that of the specimen without Nb. At 1550 and 1600℃, the wetting angle of the specimens containing Nb decreases quickly with time at first stage. After 10 min, the wetting angle reaches a steady state, and hardly changes with time. The mechanisms of Nb to improve the wettability can be attributed to the enrichment of Nb at the interface and Nb serves as surface active agent of MMS at T1550℃, and reduces the interfacial energies.

关键词： Madium Mn steel A12O3 Nb Wettalility

A hybrid method for inverse cavity scattering problem for shape

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Applied Mathematics(A Journal of Chinese Universities) 2010年第2期25卷 127-136页

作者： LIU Juan MA Fu-ming School of Mathematics, jilin university, Changchun 130012, China. School of Mathematics Jilin University Changchun China

In this paper, we give a hybrid method to numerically solve the inverse open cavity scattering problem for cavity shape, given the scattered solution on the opening of the cavity. This method is a hybrid between an iterative method and an integral equations method for solving the Cauchy problem. The idea of this hybrid method is simple, the operation is easy, and the computation cost is small. Numerical experiments show the feasibility of this method, even for cases with noise.

关键词： Open cavity Cauchy problem Helmholtz equation integral equations system method iterativehybrid method.

INFILTRATION KINETICS MODEL OF LIQUID METAL INTO A FIBROUS PREFORM IN CENTRIFUGAL ACCELERATING FIELD

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Chinese Journal of Mechanical Engineering 2001年第4期14卷 293-296页

作者： Zhang Xinping,Yu Sirong,He Zhenming (College of Materials Science and Engineering,jilin university) 吉林大学吉林

The infiltration kinetics of the metal melt into a fibrous preform in centrifugal accelerating field is analyzed on the basis of Darcy's law and the assumption that the fibrous preform is treated as 'bundle of capillaries' The critical rotating speed is analyzed with the established model The influences of the metal melt mass,the rotating speed of the equipment,the casting height, the original outer radius of the metal melt and the fibrous volume fraction in fibrous preform on infilatration are studied The results show that the critical rotating speed is dependent on critical pressure, casting height, metal melt mass and the character of fibrous preform With the increase in the metal melt mass, rotating speed of the equipment and original outer radius of the metal melt, or the decrease in casting height and fibrous volume fraction in fibrous of the metal melt,or the decrease in casting height and fibrous volume fraction in fibrous preform,infiltration of metal melt for fibrous preform becomes easier.

关键词： Centrifugal accelerating field Metal melt Fiber Infiltration kinetics Metal matrix composite

COMPUTATION OF HOPF BRANCHES BIFURCATING FROM A HOPF/PITCHFORK POINT FOR PROBLEMS WITH Z_2-SYMMETRY

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Journal of Computational Mathematics 1998年第5期16卷 403-416页

作者： Bai－sheng Wu (Department of Mathematics,jilin university, Changchun 130023, China)Tassilo Kupper (Institute of Mathematics, university of Cologne, D-50931 Koln, Germany) 吉林大学数学系吉林长春 Univeristy of Cologne 德国

This paper is concerned with the computation of Hopf branches emanating from a Hopf/Pitchfork point in a two-parametor nonlinear problem satisfying a Z2symnletry condition. Our aim is to present a new al,proach to the theoretical and computational analysis of the bifurcating Hopf branches at this singular point by using the system designed to calculate Hopf points and exploring its symmetry. It is shown that a Hopf/Pitchfork point is a pitchfork bifurcation point in the *** standard continuation and branch-switching can be used to compute these Hopf branches. In addition, an effect method based on the extended system of the singular points is developed for the computation of branch of secondary (nonsymmetric) Hopf points. The implementation of Newton's method for solving the extended system is also discussed. A numerical example is ***: Hopf/Pitchfork point, Z2-symmetry, Hopf point, bifurcation, Extended system

关键词： Hopf/pitchfork point Z_2-symmetry Hopf point bifurcation Extended system

Continuous Solutions of the First Boundary Value Problems for Nonlinear Diffusion Equations

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Acta Mathematica Sinica,English Series 1994年第1期10卷 64-71页

作者： Yin Jingxue Department of Mathematics jilin university Changchun,130023 China Department of Mathematics Jilin University Changchun China

We establish the existence of continuous solutions of the first boundary value prob- lem for nonlinar diffusion equations of the form θu/ t=div(α（u）|▽u|m-1▽u)+ （u）▽u, under the conditions that A（s）=integral from n=o to s(a1/m（σ）dσis strictly increasing and m>n-1,where n is the space ***,the uniqueness is proved for solutions with some regularities.

关键词： Math lim

A Study of LD Modulation Property by Pulse Prebias Technique

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Chinese Journal of Lasers 1997年第5期B6卷 429-434页

作者： JIN Enshun SHI Jiawei ZHANG Yujun(Dept. of Electronics Engineering, jilin university, Changchun 130023, China State KeyLaboratory on Integrated Optoelectronics, jilin university Region, Changchun 130023, China) jilin Univ Changchun China

The pulse prebias technique is firstly applied to study on the modulation properties of the LD, high speed LED, and integrated laser transmitter. The results obtained from this technique agree well with those from DC... 详细信息

关键词： modulate modulation bandwidth

ACTIVITY AND SELECTIVITY OF RUTHENIUM CARBONYL,KETENYLIDENE AND CARBIDE CLUSTER-DERIVED CATALYSTS FOR ETHYLENE HYDROFORMYLATION AND CO HYDROGENATION

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Journal of Energy Chemistry 1994年第1期 61-69页

作者： XIAO Feng-ShouDepartment of Chemistry, jilin university Changchun, jilin 130023

The ruthenium catalyst prepared from triruthenium ketenylidenecluster exhibited high catalytic activity in hydroformylation of ethylene and COhydrogenation,compared with the catalyst from[HRu（CO）].The highactivity p... 详细信息

关键词： CCO Ru ACTIVITY AND SELECTIVITY OF RUTHENIUM CARBONYL,KETENYLIDENE AND CARBIDE CLUSTER-DERIVED CATALYSTS FOR ETHYLENE HYDROFORMYLATION AND CO HYDROGENATION