Passive adaptive control of chaos in synchronous reluctance motor

The performance of synchronous reluctance motor （SynRM） degrades due to chaos when its systemic parameters fall into a certain area. To control the undesirable chaos in SynRM, a passive control law is presented in this paper, which transforms the chaotic SynRM into an equivalent passive system. It is proved that the equivalent system can be asymptotically stabilized at the set equilibrium point, namely, chaos in SynRM can be controlled. Moreover, in order to eliminate the influence of undeterministic parameters, an adaptive law is introduced into the designed controller. Computer simulation results show that the proposed controller is very effective and robust against the uncertainties in systemic parameters. The present study may help to maintain the secure operation of industrial servo drive system.     

Shrinkage-divergence-proximity locally linear embedding algorithm for dimensionality reduction of hyperspectral image

Existing manifold learning algorithms use Euclidean distance to measure the proximity of data points. However, in high-dimensional space, Minkowski metrics are no longer stable because the ratio of distance of nearest and farthest neighbors to a given query is almost unit. It will degrade the performance of manifold learning algorithms when applied to dimensionality reduction of high-dimensional data. We introduce a new distance function named shrinkage-divergence-proximity (SDP) to manifold learning, which is meaningful in any high-dimensional space. An improved locally linear embedding (LLE) algorithm named SDP-LLE is proposed in light of the theoretical result. Experiments are conducted on a hyperspectral data set and an image segmentation data set. Experimental results show that the proposed method can efficiently reduce the dimensionality while getting higher classification accuracy.     

Spectral analysis and numerical simulation for second order elliptic operator with highly oscillating coefficients in perforated domains with a periodic structure

This paper discusses the spectral properties and numerical simulation for the second order elliptic operators with rapidly oscillating coefficients in the domains which may contain small cavities distributed periodically with period ε. A multiscale asymptotic analysis formula for this problem is obtained by constructing properly the boundary layer. Finally, numerical results are given, which provide a strong support for the analytical estimates     

Accelerated Poisson-Boltzmann calculations for static and dynamic systems

We report here an efficient implementation of the finite difference Poisson-Boltzmann solvent model based on the Modified Incomplete Cholsky Conjugate Gradient algorithm, which gives rather impressive performance for both static and dynamic systems. This is achieved by implementing the algorithm with Eisenstat's two optimizations, utilizing the electrostatic update in simulations, and applying prudent approximations, including: relaxing the convergence criterion, not updating Poisson-Boltzmann-related forces every step, and using electrostatic focusing. It is also possible to markedly accelerate the supporting routines that are used to set up the calculations and to obtain energies and forces. The resulting finite difference Poisson-Boltzmann method delivers efficiency comparable to the distance-dependent dielectric model for a system tested, HIV Protease, making it a strong candidate for solution-phase molecular dynamics simulations. Further, the finite difference method includes all intrasolute electrostatic interactions, whereas the distance dependent dielectric calculations use a 15-A cutoff. The speed of our numerical finite difference method is comparable to that of the pair-wise Generalized Born approximation to the Poisson-Boltzmann method.     

Extremely low vertical-emittance beam in the accelerator test facility at KEK

Electron beams with the lowest, normalized transverse emittance recorded so far were produced and confirmed in single-bunch-mode operation of the Accelerator Test Facility at KEK. We established a tuning method of the damping ring which achieves a small vertical dispersion and small x-y orbit coupling. The vertical emittance was less than 1% of the horizontal emittance. At the zero-intensity limit, the vertical normalized emittance was less than 2.8 x 10(-8) rad m at beam energy 1.3 GeV. At high intensity, strong effects of intrabeam scattering were observed, which had been expected in view of the extremely high particle density due to the small transverse emittance.     

Temperature Dependence of the Mössbauer Effect on Prussian Blue Nanowires

Highly ordered Prussian blue nanowires with diameter of about 50 nm and length up to 4 m have been fabricated by an electrodepositing technology with two-step anodizing anodic aluminum oxide films. The Mössbauer spectra taken between 15 and 300 K indicate that the hyperfine parameters decrease as the temperature increases. The temperature dependence of the quadrupole splitting, the isomer shift and the spectra area are discussed. A decrease of Debye temperature for Prussian blue nanowires was found with respect to that of Prussian blue bulk.     

NH3的同步辐射光电离

用同步辐射光在１０．０－１１．８ｅＶ能量范围内测量了ＮＨ３的光电离效率曲线，观察到在台阶状的离子振动谱上叠加了丰富的自电离结构。通过相应振动结构分析，得到ＮＨ３分子离子基电子态的振动波数ωｅ和非谐性常数（ωｅχｅ），对于出现的自电离结构可归类于ｎｓａ１（ｎ＝５，６），ｎｐａ１（ｎ＝５，６）和ｎｐｅ（ｎ＝６，７）Ｒｙｄｂｅｒｇ系列。     

Image guide couplers used in millimeter wave integrated circuits

The dispersion and coupling characteristics of the coupled image guides are studied by using the odd-even mode principle and effective dielectric constant method. The practical design of the image guide directional couplers is presented. The experiments of 3-dB and 10-dB couplers in ka band show several good features which are very useful to millimeter wave integrated circuits with flat coupling, easy design and fabrication, mechanical stability and low losses.     

DCEL材料的包铜新工艺

通过包铜过程的分析,了解到包铜反应主要是表面化学吸附反应,ZnS颗粒表面状况对生成的CuxS性质影响很大,据此设计了淬火包铜工艺,并得到形成功率较低,抗老化性能好的DCEL粉.本文初步分析了淬火生成的CuxS相,认为它的初态处于一种高度无序状击,经一段时间可自然发生某种相变.新相比较稳定,从而可能抑制由Cu+迁移造成的老化.     

Interaction of multi-raman-processes in miniature optically pumped NH3 fir laser

The principle of Raman gain superposition was introduced to the theory of multi-Raman- processes interaction. Spectral characteristics of Raman lines from miniature NH₃-optically pumped FiR lasers were studied and measured.supported by the National Nature Science Foundation of P.R.C. and the Special Research Foundation of Doctorate Stations of P.R.C.