匹配滤波器组合及其子带分解

该文从信号分解与合成角度出发，考察匹配滤波器组合重构方程的时频域形式，研究一类基于离散正交变换的匹配滤波器组合的结构及其分类，分析离散理想滤波器及其匹配组合的滤波属性，讨论迭代匹配理想滤波器系统子带分解之特性，给出模拟实验结果。

Rotational Analysis of A^2∏u-X^2∏g System of 16O2^＋ Cation

The Doppler-limited absorption spectrum of 16O2^＋ cation was observed in the region of 11385-12100 cm^-1 by optical heterodyne velocity modulation absorption spectroscopy （OH-VMS）. The transitions were assigned to the （2, 19）, （3, 20）, and （5, 21） bands in the second negative system （A^2∏u-X^2∏g）. All the available lines measured using OH-VMS were global fitted in a nonlinear least-squares fitting procedure, and precise molecular constants （Bv, Av, Dv, pv, qv, γv） were obtained for the involved levels.

Band gap modulation of nanostructured WO_(3) nanoplate film by Ti doping for enhanced photoelectrochemical performance

Despite being a promising photoanode material for water splitting,WO_(3) has low conductivity,high onset potential,and sluggish water oxidation kinetics.In this study,we designed Ti-doped WO_(3) nanoplate arrays on fluoride-doped tin oxide by a seed-free hydrothermal method,and the effects of doping on the photoelectrochemical performance were investigated.The optimal Ti-doped WO_(3) electrode achieved a photocurrent density of 0.53 mA/cm^(2) at 0.6 V(vs Ag/AgCl),110%higher than that of pure WO_(3) nanoplate arrays.Moreover,a significant cathodic shift in the onset potential was observed after doping.X-ray photoelectron spectroscopy valence band and ultraviolet–visible spectra revealed that the band positions of Ti-doped WO_(3) photoanodes moved upward,yielding a lower onset potential.Furthermore,electrochemical impedance spectroscopy measurements revealed that the conductivities of the WO_(3) photoanodes improved after doping,because of the rapid separation of photo-generated charge carriers.Thus,we report a new design route toward efficient and low-cost photoanodes for photoelectrochemical applications.

Kinetic Energy Driven Superconductivity in the Electron Doped CobaltateNa_xCoO_2 · gH_2O

Within the charge-spin separation fermion-spin theory, we show that themechanism of superconductivity in the electron doped cobaltate Na_x CoO_2 · gH_2O is ascribed toits kinetic energy. The dressed fermions interact occurring directly through the kinetic energy byexchanging magnetic excitations. This interaction leads to a net attractive force between dressedfermions, then the electron Cooper pairs originating from the dressed fermion pairing state are dueto the charge-spin recombination, and their condensation reveals the superconducting ground state.The superconducting transition temperature is identical to the dressed fermion pair transitiontemperature, and is suppressed to a lower temperature due to the strong magnetic frustration. Theoptimal superconducting transition temperature occurs in the electron doping concentration δ ≈0.29, and then decreases for both underdoped and overdoped regimes, in qualitative agreement withthe experimental results.

Detection of Aflatoxin from Some Aspergillus sp. Isolated from Wheat Seeds

Ten seed borne fungi （Alternaria sp., Aspergillus sp., Aureobasidium sp., Cladosporium sp., Dreschslera sp., Penicillium sp., Rhizoctonia sp., Stemphylium sp., Mueor sp. and Rhizopus sp.） were isolated and identified from two wheat varieties, the highest frequency of seed borne fungi was observed on wheat cultivar site Moll4 Alternaria sp.. Their mean and standard deviation was （5.5 ~ 1.69） while the lowest frequency fungal isolated was Dreschslera sp. and Rhizopus sp.. Their mean and standard deviation was （0.1 ~ 0.64）. The aflatoxin-producing isolates appeared as gray or black colonies in the UV photographs, whereas nonproducing isolates appeared as white colonies, the plate five colony four （P5CO4） showed the positive results which means the presence of aflatoxin as compaired to the control which showed the ngative results. Ammonium Hydroxide Vapor-Induced Color Change method used which the dish was inverted and 1 or 2 drops of concentrated ammonium hydroxide solution are placed on the inside of the lid. The undersides of aflatoxin-producing colonies quickly turn plum-red after the bottom of the Petri dish has been inverted over the lid containing the ammonium hydroxide aspositive result in （P5CO4） and （P7CO4） observed. Essentially no color change occurs on the undersides of colonies that are not producing aflatoxinsthis indicate to the negative results （control）. The main objective of this study is to isolation, identification and rapid detection of aflatoxin from wheat seed borne fungi.

A method to compress vibration signals using wavelet packet transformation combined with sub-band vector quantization

A novel compression method for mechanical vibrating signals,binding with sub-band vector quantization(SVQ) by wavelet packet transformation(WPT) and discrete cosine transformation(DCT) is proposed.Firstly,the vibrating signal is decomposed into sub-bands by WPT.Then DCT and adaptive bit allocation are done per sub-band and SVQ is performed in each sub-band.It is noted that,after DCT,we only need to code the first components whose numbers are determined by the bits allocated to that sub-band.Through an actual signal,our algorithm is proven to improve the signal-to-noise ratio(SNR) of the reconstructed signal effectively,especially in the situation of lowrate transmission.

An Improved Prediction Model of Vortex Shedding Noise from Blades of Fans

The main source of the noise of an axial flow fan is the fluctuating pressure field on blade surfaces caused by the shedding of vortices at the trailing edge of blades.An analytical model to predict the vortex shedding noise generated at the trailing edge of blades of axial flow fans was proposed by Lee in 1993.In this model,for mathematical convenience,an idealized vortex street is considered.However,the agreement between the analytical results and the experimental data needs to be improved because of the simplification about the Karman vortex street in the wake of blade.In the present study,a modified model is proposed based on the prediction model by Lee.The boundary layer theory is used to analyze and calculate the boundary layer development on both the pressure and the suction sides of blades.Considering the effect of boundary layer separation on the location of noise source,the predicted overall sound pressure level compares favorably with the experimental data of an axial fan.In the calculation of A-weighted sound pressure level(La),considering the effect of static pressure on radiate energy,the predicted broadband noise with the modified model compares favorably with the experimental data of a multiblade centrifugal fan.