Optimal Filtering Algorithm for Stochastic 2-D FMM Ⅱ with Multiplicative Noise

1　Introduction　Inrecentyearstherehasbeengrowingresearchin terestinthetwo dimensional (2 D )systemtheory .The 2 Dsystemsmayfindapplicationsinareassuchasmarineseismicdataprocessingandimageprocessing .Althoughmoreandmorevaluableresultshavebeengained ,mos…     

Photopolarimetric studies of comet Austin

Photopolarimetric observations of comet Austin with the IAU/IHW filter system were obtained on the 2.34 m Vainu Bappu Telescope (VBT) of the Indian Institute of Astrophysics, at Kavalur, India, during pre-perihelion phase on February 20,1990 and on the 1.2 m telescope of the Physical Research Laboratory at Gurusikhar, Mount Abu during postperihelion phase on May 2 and 4, 1990. The comet appeared bluer than a solar analog during post-perihelion phase on May 2 and 4. The percent polarization shows a sharp increase towards the red on May 2 and 4. The dominant sizes of the dust particles appear to lie in a narrow range of 0.1 to 0.5 Μm. Regarding the molecular band emission, CN and C₂ bands are quite strong; C₃ emission was also found to be strong though the observations on May 2 and 4 show significant variation as compared to C₂ emission. Molecular band polarization for CN, C₃, C₂ and H₂ O+ have been calculated. It has been found that emission polarization in CN, C₂ and C₃ is between 1–7% (phase angle between 107.4–109 degrees). For CN and C₂ the polarization values are close to the theoretically predicted values, but for C₃ the polarization value falls much below the theoretically predicted value. A similar result was found for comet Halley.     

居民收入与通信网络市场经济效益研究--以河北省通信网络为实例

利用Logisitic曲线模型和扩展支撑模型对居民可支配收入预测和单项消费预测，以河北省居民的收入及其消费支出为实例，研究了城镇居民和农民的可支配收入分配和单项边际消费倾向，合理建立了预测模型，并理论计算了1999～2003年的通信消费方面的边际消费倾向、预测了2004～2008年通信消费情况。最后，根据预测结果对通信网络建设提出了一些有价值的建议。     

The depolarization properties of powerful extragalactic radio sources as a function of cosmic epoch

We use the observed polarization properties of a sample of 26 powerful radio galaxies and radio-loud quasars to constrain the conditions in the Faraday screens local to the sources. We adopt the cosmological redshift, low-frequency radio luminosity and physical size of the large-scale radio structures as our 'fundamental' parameters. We find no correlation of the radio spectral index with any of the fundamental parameters. The observed rotation measure is also independent of these parameters, suggesting that most of the Faraday rotation occurs in the Galactic foreground. The difference between the rotation measures of the two lobes of an individual source, as well as the dispersion of the rotation measure, shows significant correlations with the source redshift, but not with the radio luminosity or source size. This is evidence that the small-scale structure observed in the rotation measure is caused by a Faraday screen local to the sources. The observed asymmetries between the lobes of our sources show no significant trends with each other or other source properties. Finally, we show that the commonly used model for the depolarization of synchrotron radio emission by foreground Faraday screens is inconsistent with our observations. We apply alternative models to our data and show that they require a strong increase of the dispersion of the rotation measure inside the Faraday screens with cosmological redshift. Correcting our observations with these models for redshift effects, we find a strong correlation of the depolarization measure with redshift and a significantly weaker correlation with radio luminosity. We do not find any (anti-)correlation of depolarization measure with source size. All our results are consistent with a decrease in the order of the magnetic field structure of the Faraday screen local to the sources for increasing cosmological redshift.     

Anomalous Behavior of the Linear Polarization of the Herbig Ae Star WW Vul during the 1997 Minimum

In the course of photopolarimetric monitoring of the Herbig Ae star WW Vul, an unusual variation of linear polarization upon energence from a deep minimum was recorded, which cannot be explained by the standard mechanism for such objects (UX Ori stars): a variable contribution of radiation scattered by circumstellar dust. An analysis of possible causes of the anomalous behavior of polarization shows that it was most likely due to the presence of aligned, aspherical dust grains in the dust cloud crossing the line of sight at that time.     

A high resolution,multiproxy Late‐glacial record of climate change and intrasystem responses in northwest England

A lacustrine carbonate sequence from Hawes Water, Lancashire, UK, has been studied using stable isotopic, lithological, pollen and mineral magnetic analysis. The data reveal four abrupt climatic oscillations in the Late‐glacial Interstadial leading up to the onset of the Loch Lomond Stadial. The data also point to climatic warming relatively early within the stadial, ca. 12 500 GRIP yr, prior to the onset of the Holocene. The oxygen isotope record is taken as a signature of climate forcing against which the response of the lake‐system can be monitored. By adopting this approach it is revealed that the response of the biological system to the rapid climatic oscillations is non‐linear and primarily a function of the antecedent conditions. A significant end‐Devensian isotopic excursion (A) is matched by only minor changes in the cold‐adapted floras and faunas. During the warmer interstadial, the response of the biological ecosystem (events B–D) is clearly influenced by thresholds: major changes in the catchment vegetation associated with relatively minor oscillations in the isotopic signature. The stratigraphical patterns reveal significant lag effects between the onset of climate deterioration and resulting changes in vegetation. Copyright © 2002 John Wiley & Sons, Ltd.     

冰雹云雷达回波自动识别系统

利用CAPPI资料对立体风暴进行识别，计算并提供出实用的风暴结构参数，采用矩心踊跃法和矩不变量法相结合对单体风暴和混合性风暴回波进行跟踪；最小二第线性外推预报；根据WSD－88D的冰雹算法，在风暴结构基础上本文建立了Windows98操作平台上冰雹识别系统，经单站1年11次强对流天气过程的资料检验，结果表明：雹云识别精度达82％。系统建立了大量人机对话框以方便用户，增加实用性及推广性。     

CCD Polarimetric Imaging Of Comet Hale-Bopp (C/1995 O1)

Polarimetric observations of the light scattered by dust have been carried out at Pic-du-Midi Observatory with the 2 m telescope in June and September–October 1996, and at Haute-Provence Observatory with the 0.80 m telescope in April 1997. They cover a total number of 11 nights and a large (6.9°–47.7°) phase angle range. The spatial resolution allows to underline structures in the coma, as well in the brightness images as in the polarization maps, with a correlation between the regions of bright structures and the regions of higher polarization. A clear difference appears between the sunward and antisunward side, with higher polarization on the antisunward side. The phase angle coverage allows us to obtain a polarimetric phase curve for the whole coma and to compare it with other cometary phase curves. The degree of polarization is higher for Hale-Bopp than for the comets previously observed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Scattered light models of the dust shell around HD 179821

The dust shell around the evolved star HD 179821 has been detected in scattered light in near-IR imaging polarimetry observations. Here, we subtract the contribution of the unpolarized stellar light to obtain an intrinsic linear polarization of between 30 and 40 per cent in the shell that seems to increase with radial offset from the star. The J - and K -band data are modelled using a scattering code to determine the shell parameters and dust properties. We find that the observations are well described by a spherically-symmetric distribution of dust with an r ⁻² density law, indicating that when mass-loss was occurring, the mass-loss rate was constant. The models predict that the detached nature of a spherically-symmetric, optically-thin dust shell, with a distinct inner boundary, will only be apparent in polarized flux. This is in accordance with the observations of this and other optically-thin circumstellar shells, such as IRAS 17436+5003. By fitting the shell brightness we derive an optical depth to the star that is consistent with V -band observations and that, assuming a distance of 6 kpc, gives an inner-shell radius of     , a dust number density of     at r _in and a dust mass of     . We have explored axisymmetric shell models but conclude that any deviations from spherical symmetry in the shell must be slight, with an equator-to-pole density contrast of less than 2:1. We have not been able to fit simultaneously the high linear polarizations and the small     colour excess of the shell and we attribute this to the unusual scattering properties of the dust. We suggest that the dust grains around HD 179821 either are highly elongated or consist of aggregates of smaller particles.