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Advances in studies of the tribological behavior of molecular deposition films

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Petroleum science 2008年第4期5卷 379-387页

作者： Xiao Yuqi Zhang Siwei Wang Deguo Gao Manglai school of mechanical and {2. engineering China University of Petroleum Beijing 102249 China school of Chemical science and {2. China University of Petroleum Beijing 102249 China

An overview of the advances in studies on tribology of molecular deposition （MD） films is presented here to summarize the studies of nanofrictional properties, adhesion, wear and mechanical behavior, as well as the molecular dynamics simulation of nanotribological properties of the film in the last decade. Some key research topics which need to be investigate further are addressed.

关键词： Molecular deposition (MD) film tribological behavior adhesive property wear characteristics mechanical behavior

Structures and stability of isomers of[Si,N,N,P]system

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science china Chemistry 2004年第2期47卷 98-105页

作者： KAN Wei1, YU Haitao1, LI Mingxia1, FU Honggang1,2.& SUN Jiazhong1,2.1. College of Chemistry and Chemical engineering, Heilongjiang university, Harbin 150080, {2. 2. State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin university, changchun 13002., {2. 1. College of Chemistry and Chemical engineering Heilongjiang University 150080 Harbin China 2. State Key Laboratory of Theoretical and Computational Chemistry Institute of Theoretical Chemistry Jilin University 130023 Changchun China

Some stationary points on the potential energy surface of [Si, N, N, P] system were located at the B3LYP/6-311G(d) and QCISD(t)/6-311+G(2.f)(single-point) levels of theory, while the isomerization, structures, and stability of these obtained isomers were suggested. The computed results indicate that only four-membered ring isomer SiNPN(E1, 2.'), which possesses butterfly-like structure and Si-P cross bonding, is kinetically stable in all optimized isomers. Other isomers may be considered as kinetically unstable towards isomerization or dissociation because of the corresponding smaller reaction barriers. Furthermore, the present paper also proposes electronic and geometric structures, vibrational frequencies and the corresponding vibrational modes, dipole moments, and rotational constants of isomer E1. To make use of the computed results, we can clearly know that the reaction pathway via an intermediate E3 (SiNPN) is the most favorable channel producing isomer E1 from fragments SiN(2.) and PN (1Σ), which have been well characterized in space, and thus, isomer E1 can be considered as a candidate for interstellar observation. The reaction enthalpy of SiN(2.) + PN(1Σ)→ E1 and the standard enthalpy of formation of isomer E1 are 2.5.2. and 457.99 kJ/mol, respectively, at 2.8.15 K. Keywords potential energy surface - [Si,N,N,P] system - isomerization - kinetic stability

关键词： potential energy surface, [Si,N,N,P] system, isomerization, kinetic stability.

基于GSPN方法的柔性制造系统过程模型和性能分析(英文)

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系统仿真学报 2008年第19期20卷 5258-5261页

作者：马增治王龙山高洪吉林大学机械科学与工程学院长春130025 长春大学机械工程学院长春130022

应用广义随机Petri网方法,对柔性制造系统进行建模和分析,提出了控制策略和优化方法。针对柔性制造系统的离散性,对整个系统的过程模型进行分析。利用广义随机 Petri 网结合马尔可夫链的方法,确立了系统的配置参数,得出了系统的平均运... 详细信息

应用广义随机Petri网方法,对柔性制造系统进行建模和分析,提出了控制策略和优化方法。针对柔性制造系统的离散性,对整个系统的过程模型进行分析。利用广义随机 Petri 网结合马尔可夫链的方法,确立了系统的配置参数,得出了系统的平均运行时间,机床的平均使用率,系统的生产率,故障概率,对系统的优化和生产效率的提高以及柔性的提高提供了理论支持。最后,通过柔性制造系统实例,对该方法进行了检验。

关键词：广义随机Petri 网(GSPN) 柔性制造系统马尔可夫链过程模型

Orbital-abrasion-assisted Electroforming of Non-rotating Parts

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Journal of Wuhan university of Technology(Materials science) 2011年第5期26卷 827-831页

作者：李学磊 Nanjing university of Aeronautics & Astronautics school of mechanical & {2. engineering Shanghai Second Polytechnic University

A novel technique of electroforming with orbital moving cathode was carried out for the fabrication of non-rotating thin-walled *** technique features a large number of insulating and insoluble hard particles as a real-time polishing to the *** cathode moves,hard particles polish its surface and provide the nickel non-rotating parts with near-mirror ***,microstructure,surface roughness and micro hardness of deposits fabricated by novel method were studied in contrast with the sample produced by traditional electroforming *** analysis and experimental results showed that the novel technique could effectively remove the hydrogen bubbles and nodules,disturb the crystal nucleation,and refine the grains of *** mechanical properties were significantly improved over traditional *** micro-hardness of the layer was in a uniform distribution ranging from 345 HV to 360 *** was confirmed that this technique had practical significance to non-rotating thin-walled parts.

关键词： electroforming orbital cathode abrasion non-rotating parts

Nanomechanical Properties of Molecular Deposition Film

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Journal of Wuhan university of Technology(Materials science) 2005年第3期20卷 20-22页

作者：兰惠清 school of mechanical Electronic and Control Engineering Beijing Jiaotong University

Two nanomechanical properties of the moleculor deposition （ MD ） film deposited on the Au substrate were studied. The first is its nanotribological property investigated by an atomic force microscope, which indicates that the deposition of the MD film could reduce the frictional force. The second is its nanoindent property studied by a nano-indenter. The results show that, after the MD film is deposited on the Au substrate , the elastic modulus, hardness and load decreased all, moreover, the elastic deformation increased and the plastic deformation decreased, which indicates that the MD film can improve the nanomechanical properties of the Au substrate.

关键词： molecular deposition film atomic force miroscope nanomechanical properties nanoindent

Characteristic atom arranging crystallogphy of alloy phases for Au-Cu system

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science china(Technological sciences) 2011年第6期54卷 1560-1567页

作者： XIE YouQing1,2.3,LIU XinBi1,2.3,PENG HongJian4,NIE YaoZhuang5,LI XiaoBo6 & LI YanFen1,2.3 1 school of Materials science and {2.,Central South university,Changsha 410083,china 2.Powder Metallurgy Research Institute,Central South university,Changsha 410083 china 3 State Key Laboratory of Powder Metallurgy,Central South university,Changsha 410083,china 4 school of Chemistry and Chemical {2.,Central South university,Changsha 410083,china 5 school of Physical science and Technique,Central South university,Changsha,410083,china 6 College of mechanical {2.,Xiangtan university,Xiangtan 411105,china 1. school of Materials science and {2. Central South University Changsha 410083 China2. Powder Metallurgy Research Institute Central South University Changsha 410083 China3. State Key Laboratory of Powder Metallurgy Central South University Changsha 410083 China4. School of Chemistry and Chemical Engineering Central South University Changsha 410083 China5. School of Physical Science and Technique Central South University Changsha 410083 China6. College of Mechanical Engineering Xiangtan University Xiangtan 411105 China

In this paper,it is pointed out that the descriptions of alloy phase structures are dependent on structural unit *** the systematic science of alloys(SSA),the alloy phase structures are described by means of the symmetry element sequence combining with characteristic atom *** is named the characteristic atom arranging structure,which can display the characteristic atoms at the lattice sites and the micro-inhomogeneity,besides the *** characteristic atom has its own characters:neighboring configuration,potential energy,volume and electronic *** micro-inhomogeneity of alloy phases can be described by concentrations and short-range ordered parameters of characteristic *** differences between the electronic structures of alloy phases and electronic structures of characteristic atoms in the alloy phases are also discussed.

关键词： systematic science of alloys Au-Cu system alloy phase structure micro-inhomogeneity

DFT evaluation of the electronic structures and spectroscopic properties of the self-assembled [Pt_2._4(C≡CH)_8](M=Cu,Ag) clusters

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science china Chemistry 2009年第11期52卷 1954-1960页

作者： BAI FuQuan1,XIA BaoHui1,2.ZHANG HongXing1,YANG BaoZhu1,WANG Jian1 & SUN Lei1 1 State Key Laboratory of Theoretical and Computational Chemistry,Institute of Theoretical Chemistry,Jilin university,changchun 13002.,{2. 2.College of Chemistry,Jilin university,changchun 13002.,{2. State Key Laboratory of Theoretical and Computational Chemistry Institute of Theoretical Chemistry Jilin University Changchun 130023 China College of Chemistry Jilin University Changchun 130023 China

electronic structures and spectroscopic properties of self-assembled [Pt2.4(C≡CH)8](M=Cu,Ag) clusters have been studied by the TD-DFT(time-dependent density functional theory) calculations with the polarizable continuum model(PCM).The ground-and excited-state structures were optimized by the DFT(density functional theory) *** calculated structures and spectroscopic properties are in agreement with the corresponding experimental *** [Pt2.g4(C≡CH)8] clusters have two stable ground state geometries(D4 and D4h symmetry).The calculated Pt-M distances suggest only very weak *** Cu-Cu distances are larger than the van der Waals radii of two Cu atoms and the Ag-Ag distances are analogous with the sum of van der Waals radii of two Ag *** excitation,the interaction of Pt…M,Ag…Ag is strengthened,while the Cu…Cu distances are shortened but they are still larger than the sum of van der Waals radii of two Cu *** lowest-energy absorptions are at 450,365 and 375 nm and the emissions are at 611,431 and 435 nm for [Pt2.u4(C≡CH)8],[Pt2.g4(C≡CH)8](A) and(B),*** transitions are all perturbed by the Cu or Ag composition through the UV-Vis spectra region;therefore,there are not pure ILCT or MPtLCT characteristics(ILCT:intraligand charge transfer;MLCT:metal-to-ligand charge transfer) in absorptions of heteropolynuclear [Pt2.4(C≡CH)8] *** the emissions and the lowest-absorptions have different transition characteristics for each complex,the emissions should not come from the lowest-energy *** the M…M interactions in the excited state of [Pt2.g4(C≡CH)8] are augmented,the emissions of [Pt2.g4(C≡CH)8] clusters bear prominent ILCT character,which is the reason why the emission wavelengths of [Pt2.g4(C≡CH)8] have a small hypsochromic shift relative to the emission wavelength of homoleptic [Pt(C≡CH)4]2.precursor.

关键词： electronic structures luminescence behavior heteropolynuclear complexes TDDFT

Effects of NaNbO_3-Co_2._3 Co-additive on the Properties of PZN-PZT Ceramics

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Journal of Wuhan university of Technology(Materials science) 2007年第4期22卷 722-724页

作者：邓毅华 College of Material science and engineering South China University of Technology Department of electronic science and Technology Huazhong University of Science and TechnologyWuhan 430074China

NaNbO3-Co2.3 co-added PZN-PZT （PZCNNT） ceramics were prepared using conventional solid state reaction. The piezoelectric and dielectric properties were measured. The experimental results show that the addition of 0.3mo1% Co2.3 leads to low dielectric loss （tgδ） in PZCNNT ceramics and the proper addition of NaNbO3 not only improves piezoelectric properties but also decreases intensively dielectric loss and mechanical loss. The optimal ceramic having d33=310 pC/N, kp=0.59, εr=985, tgδ=0.0034, Qm=1380 was obtained.

关键词： PZN-PZT piezoelectric constant dielectric constant dielectric loss

Study on Ceramic Cutting by Plasma Arc

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厦门大学学报（自然科学版） 2002年第S1期41卷 55-56页

作者： XU Wen-ji 1, FANG Jian-cheng 2. LU Yi-shen 1 (1. school of mechanical {2., Dalian university of Technology, Dalian 11602., china 2. College of mechanical {2. and Automation, Huaqiao university, Quanzhou 362.11, china)

engineering ceramics are typical difficult-to-machine materials because of high hardness and brittleness. PAC (Plasma Arc Cutting) is a very important thermal cutting process and has been successfully used in cutting stainless steel and other difficult-to-machine alloys. PAC’s application in cutting ceramics, however, is still limited because the most ceramics are not good electronic conducts, and transferred plasma arc cannot be produced between cathode and work-piece. So we presented a method of plasma arc cutting engineering ceramics with additional anode. To reduce the kerf width and to improve the kerf quality, the hydro-magnetically confined plasma arc is used to cut engineering ceramic plates. By experiments and analyses the mechanism and characteristics of hydro-magnetic confined plasma are discussed and the effects of secondary confinement on cutting quality, arc properties, and optimal process parameters are presented. When the nozzle diameter is 3 mm, the kerf width of the Al 2. 3 ceramic plate with 6 mm thickness is less than 4.6 mm, and the cutting speed reaches to 0.9～1.2.m/min. Both theoretical analysis and experimental results have proved the feasibility and validity of the newly advanced hydro-magnetic plasma arc cutting, and the following conclusion can be drawn: (1)Synthesizing the advantages of both the water-constriction and magnetic constriction, the hydro-magnetic constriction of plasma arc forms a three-dimensional constriction with improved shape and uniformity of arc column, narrower kerfs, minimal beveling of cuts and higher dross-free cutting speeds than those under either water-constriction or magnetic constriction alone.(2.Hydro-magnetic constriction is capable of improving arc stability, which is reflected in the higher arc voltage at which arc-extinction occurs, than that under any single constriction. (3)For a given diameter of nozzle, quality cut can be produced by using a lower arc current than usually required in conventional plas

关键词： plasma cutting engineering ceramic plasma confinement