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挤压油膜阻尼器对转子振动进行分段控制有效性的试验研究 总被引:2,自引:0,他引:2
本文从试验上研究了可调参数挤压油膜阻尼器(VPSFD)对柔性转子系统振动进行分段变参控制的有效性。结果说明了利用VPSFD对转子系统的振动进行分段变参控制不仅可以减小转子系统的振动,而且还能够使转子平稳地通过具有较大振动的共振区及避免出现具有极大振动的双稳态,具有良好的控制效果。 相似文献
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在分析SDL语言文法的基础上,构造了SDL/FOP的文法形式,并在SDL/FOP的定义中保持了SDL语言各种语法成分的相互关系,从而证明了SDL语言与离散形式的SDL/FOP是等价的,最后给出了SDL/PR到SDL/FOP转换系统的实现算法。 相似文献
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高性能热塑性树脂增韧聚苯硫醚的韧性 总被引:3,自引:0,他引:3
研究了高性能热塑性树脂双酚A型聚砜(PSF)、酚酞型聚醚酮(PEK-C)增韧聚苯硫(PPS)的破坏韧性和破坏形态。实验表明:PSF与PEK-C两种材料的加入都能改善PPS的冲击强度和破坏韧性。不同共混(加入)方法对PSF/PPS与PEK/-C/PPS两体系的增韧效果有效果。 相似文献
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介绍了在聚乙烯醇缩甲醛(PVF或Formvar)膜上蒸镀Au,Pd和Ag金属膜,用XPS研究其表面与界面的化学组分与价态。实验发现,在PVF膜上蒸膜上Au,Pd和Ag后,三咱不同价态的CIS相对含量均发生变化。表明金属原子在PVF膜上沉积上是化学吸附。 PS 相似文献
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溶胶—凝胶法有机—无机精细复合材料P(VDF/TeFE)—SiO2的制备与显微 … 总被引:6,自引:0,他引:6
用溶胶-凝胶法制备了有机-无机精细复合材料P(VDF/TeFE)-SiO2。利用水解-聚合反应由正硅酸乙酯(TEOS)合成SiO2溶胶,乙醇作溶剂,盐酸作催化剂。将P(VDF/TeFE)溶于丙酮,并与SiO2溶胶均匀混合。凝胶后经干燥和热处理得到有机-无机精细复合材料P(VDF/TeFE)-SiO2。用红外光谱分析、扫描电镜分析、差示扫描热分析和热失重分析对有机-无机精细复事材料P(VDF/TeF 相似文献
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掺杂聚苯胺磁化率的研究 总被引:6,自引:0,他引:6
分别研究了浓H2SO4掺杂本征态聚苯胺(PAn)、HCl掺杂PAn以及FeCl3掺杂这两种聚安在地的磁化率。通过研究磁化率的变化曲线,我们得到了一些有意义的结果:浓H2SO4掺杂PAa和HCl掺杂PAn的磁化率变化规律不同;FeCl3掺杂浓H2SO4-PAn材料可以获得比FeCl3掺杂HCl-PAn材料更高的磁化率;FeCl3在掺杂HCl-PAn材料和浓H2SO4-PAn材料时,FeCl3在这两种 相似文献
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Abstract In order to understand the velocity depending effect in an FPS isolator and to verify its ability to achieve the desired dynamic friction coefficient, individual FPS isolators, both 1/4 and full size model, were tested. In addition, a two‐story frame model was tested on a shaking table [10] to investigate the feasibility of FPS connections. The characteristics of the friction coefficient of FPS bearing were studied and it was confirmed that FPS connections are able to achieve seismic isolation by dissipating the earthquake input energy during sliding. An analytical model of the test structure containing the mathematical expressions of the velocity depending effects is employed in the analysis, and the theoretical results agree strongly with the experimental results. 相似文献
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A method for calculating normal forms for non-autonomous periodically perturbed Hamiltonian systems is developed. The solution for an autonomous Hamiltonian normal form is well known, and involves the solution of a homological equation on the vector space of homogeneous scalar polynomials. An algorithm is presented for generating an analogous non-autonomous homological equation using Lie transforms. Solution of this equation will generate a normal form for the non-autonomous Hamiltonian. Although this equation is defined on an infinite-dimensional space, it is shown that the problem can be reduced to an equivalent one on a finite-dimensional space. A solution can then be found in an analogous way to the solution for the autonomous problem. It is also shown that the normal form satisfies invariance properties. Finally, an example problem is presented to illustrate the solution technique. 相似文献
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A two-dimensional model is suggested of dc glow discharge with parallel electrodes. The model includes equations for electron and ion concentrations, which are related to the Poisson equation for electric potential. The collision ionization and electron-ion recombination are described using empirical relations. Processes of vibrational excitation of N2 molecules are considered. The vibrational kinetics of nitrogen are described in view of excitation by electron impact, vibrational exchange, and vibrational-translational relaxation. The finite-difference model used for solving kinetic equations is described. Results are obtained for a two-dimensional model of glow discharge in nitrogen at a pressure of 5 torr and an emf of 2000 V. The obtained fields of distribution of electron temperature and populations of vibrational levels of nitrogen are analyzed. The results enable one to estimate the fraction of electric field energy utilized for the excitation of vibrational states. 相似文献
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A new hologram type in spectral hole-burning systems is presented. During exposure, the frequency of narrow-band laser light is swept over a spectral range that corresponds to a few homogeneous linewidths of the spectrally selective recording material. Simultaneously the phase of the hologram is adjusted as a function of frequency-the phase sweep function. Because of the phase-reconstructing properties of holography, this recording technique programs the sample as a spectral amplitude and phase filter. We call this hologram type frequency and phase swept (FPS) holograms. Their properties and applications are summarized, and a straightforward theory is presented that describes all the diffraction phenomena observed to date. Thin FPS holograms show strongly asymmetric diffraction into conjugated diffraction orders, which is an unusual behavior for thin transmission holograms. Investigations demonstrate the advantages of FPS holograms with respect to conventional cw recording techniques in freq ncymultiplexed data storage. By choosing appropriate phase sweep functions, various features of holographic data storage can be optimized. Examples for cross-talk reduction, highest diffraction efficiency, and maximal readout stability are demonstrated. The properties of these FPS hologram types are deduced from theoretical considerations and confirmed by experiments. 相似文献
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We address the problem of unidirectional guidepath layout design for automated guided vehicle systems- A two-step layout design method to consider both loaded and empty vehicle movements is developed to guarantee a complete layout design. First, the flow path selection (FPS) problem is formulated to design guidepath layout with the objective of minimizing loaded vehicle movements. Both a mathematical model and a heuristic algorithm for FPS are presented. Since AGV guidepath layouts are used by both loaded and empty vehicles, the FPS does not guarantee a closed or complete layout design. For the case when an incomplete or unclosed layout is produced from the first step, a complementary layout design (CLD) approach to convert the incomplete layout into complete one with the consideration of empty vehicle movements is considered in the second step. A heuristic for the CLD problem is developed. An example problem is used to illustrate the whole design approach. 相似文献
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An interval-fuzzy quadratic programming (IFQP) method is developed for the assessment of filter allocation and replacement strategies in fluid power systems (FPS) under uncertainty. It can directly handle uncertainties expressed as interval values and/or fuzzy sets that exist in the left-hand and right-hand sides of constraints, as well as in the objective function. Multiple control variables are used to tackle independent uncertainties in the model's right-hand sides and thus optimize the overall satisfaction of the system performance. The IFQP method is applied to a case of planning filter allocation and replacement strategies under uncertainty for an FPS with a single circuit. A piecewise linearization approach is firstly employed to convert the nonlinear FPS problem into a linear one. The generated decision alternatives can help decision makers to identify desired policies for contamination control under various total costs, satisfaction degrees, and system-failure risks under different contaminant-ingression/generation rates. 相似文献
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A. N. Aleshin Yu. F. Biryulin N. B. Mironkov L. V. Sharonova E. N. Fadeeva V. N. Zgonnik 《Fullerenes, Nanotubes and Carbon Nanostructures》1998,6(3):545-561
Polystyrene and polyethyleneoxide films both containing fullerene, C60, designated as FPS and FPEO were investigated by the ellipsometry, photoluminescence spectra and electrical dc conductivity methods. The FPS and FPEO films display complex refractive index of 1.7 - 10.05 and 1.45 - 10.0 respectively. The photoluminescence maximum attributed to C60 shifted to higher photon energies proportionally to with the increase of the number of the polymer rays attached. The shift can be described by the linear relationship ΔE=004N, where ΔE is the shift in eV and N is the number of polymer rays attached. The magnitude of dc conductivity exhibited by the FPS films varied directl proportionally to molar concentration of C60 相似文献
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A. N. Aleshin Yu. F. Biryulin N. B. Mironkov L. V. Sharonova E. N. Fadeeva V. N. Zgonnik 《Fullerenes, Nanotubes and Carbon Nanostructures》2013,21(3):545-561
Abstract Polystyrene and polyethyleneoxide films both containing fullerene, C60, designated as FPS and FPEO were investigated by the ellipsometry, photoluminescence spectra and electrical dc conductivity methods. The FPS and FPEO films display complex refractive index of 1.7 ? 10.05 and 1.45 ? 10.0 respectively. The photoluminescence maximum attributed to C60 shifted to higher photon energies proportionally to with the increase of the number of the polymer rays attached. The shift can be described by the linear relationship ΔE=004N, where ΔE is the shift in eV and N is the number of polymer rays attached. The magnitude of dc conductivity exhibited by the FPS films varied directl proportionally to molar concentration of C60 相似文献