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61.
62.
本文介绍JDH型转差离合器控制装置的组成,速度调节器采用PID控制并加入惯性环节。采用TCA785移相触发器。通过参数的合适匹配,可使系统获得理想的动态品质和控制效果。 相似文献
63.
陈晓玥 《南阳理工学院学报》2014,(4):41-45
本文选取2005-2011年的有关数据,运用动态偏离-份额法对福建省九大地区的第三产业产值进行分析,并根据分析结果提出提高福建省第三产业竞争力的政策建议。 相似文献
64.
Xiliang Fan 《随机分析与应用》2015,33(2):199-212
By using coupling by change of measures, the Driver-type integration by parts formula is established for a class of stochastic differential equations driven by fractional Brownian motions. As applications, (log) shift Harnack inequalities and estimates on the distribution density of the solutions are presented. 相似文献
65.
Value sharing results for shifts of meromorphic functions, and sufficient conditions for periodicity 总被引:1,自引:0,他引:1
This research is a continuation of a recent paper due to the first four authors. Shared value problems related to a meromorphic function f(z) and its shift f(z+c), where c∈C, are studied. It is shown, for instance, that if f(z) is of finite order and shares two values CM and one value IM with its shift f(z+c), then f is a periodic function with period c. The assumption on the order of f can be dropped if f shares two shifts in different directions, leading to a new way of characterizing elliptic functions. The research findings also include an analogue for shifts of a well-known conjecture by Brück concerning the value sharing of an entire function f with its derivative f′. 相似文献
66.
Yu’e An 《Journal of Computational and Applied Mathematics》2010,234(8):2420-2431
In this paper, we present a new method of model reduction for large-scale dynamical systems, which belongs to the SVD-Krylov based method category. It is a two-sided projection where one side reflects the Krylov part and the other side reflects the SVD (observability gramian) part. The reduced model matches the first r+i Markov parameters of the full order model, and the remaining ones approximate in a least squares sense without being explicitly computed, where r is the order of the reduced system, and i is a nonnegative integer such that 1≤i<r. The reduced system minimizes a weighted ?2 error. By the definition of a shift operator, the proposed approximation is also obtained by solving an equality constrained least squares problem. Moreover, the method is generalized for moment matching at arbitrary interpolation points. Several numerical examples verify the effectiveness of the approach. 相似文献
67.
在放电间隙较大的介质阻挡放电中,利用高速照相机,同时观察到了体放电(VD)和沿面放电(SD)。采用光谱法,研究了VD和SD的光谱线形随放电参数的变化。在氩气介质阻挡放电中,测量了VD和SD的Ar Ⅰ(2P2→1S5)谱线展宽和频移随气压及放电间隙的变化。结果发现:SD的展宽和频移均比VD的大,说明SD的电子密度高于VD的电子密度;随着压强从40 kPa增大到60 kPa,VD和SD的谱线展宽及频移均增加,表明它们的电子密度均随压强的增大而升高;随着d值从3.8 mm增大到4.4 mm,VD和SD的谱线展宽也增加,反映它们的电子密度均随d值的增大而增加。 相似文献
68.
Hyperfine structure and isotope shifts in the 5d6s2 a2D3/2--5d6s(a3D)6p z4F5/2
° transition of Hf II
W.Z. Zhao F. Buchinger J.E. Crawford S. Fedrigo S. Gulick J.K.P. Lee O. Constantinescu M. Hussonnois J. Pinard 《Hyperfine Interactions》1997,108(4):483-495
The hyperfine structure and isotope shifts of the transition between the 5d6s2 a2D3/2 ground state and the 5d6s(a3D)6p z4F5/2
° excited state of singly ionized hafnium at \lambda=340 nm have been investigated by laser spectroscopy using a radio-frequency
quadrupole ion trap. The magnetic dipole coupling constant A and electric quadrupole coupling constant B of the two atomic
levels for both stable isotopes 177Hf and 179Hf are determined. The changes of mean square nuclear charge radii \delta[ r2] of the stable Hf isotopes and the radioactive isotope 172Hf (T1/2=1.87a) have been extracted from the data.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
69.
Aqueous cobalt(II) ion is shown to be an effective chemical shift reagent for nitrogen-14 nuclear magnetic resonance spectroscopy. Addition of an 8 fold excess of cobalt (II) ion to a mixture of betaine, glycerophosphorylcholine and ammonium ion results in baseline resolution of the three components. The chemical shift of each component is a function of cobalt concentration up to a molar ratio of about 4:1 after which, the shifts 相似文献
70.
Joseína Moutinho Tavares de Souza Maria do Carmo Rangel 《Reaction Kinetics and Catalysis Letters》2002,77(1):29-34
The replacement of chromium by aluminium in high temperature shift catalysts was investigated. It was found that aluminium-doped hematite is a convenient candidate as an environmental friendly catalyst. 相似文献