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On the Spectral Index-Flux Density Relation for Large Samples of Radio Sources

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Chinese Journal of Astronomy and Astrophysics 2003年第4期3卷 347-358页

作者： Xi-ZhenZhang w.reich P.reich R.wielebinski NationalAstronomicalObservatories ChineseAcademyofSciencesBeijing100012 Max-Planck-InstitutfuerRadioastronomie AufdemHuegel69D-53121BonnGermany

we present new statistical results on the spectral index-flux density relation for large samples of radio sources using archival data of the most sensitive surveys, such as 6C, Miyun, wENSS, B3, NVSS, GB87. Instrumental selection effects and the completeness of the catalogs are discussed. Based on the spectral indices calculated for about 200 000 sources from the wENSS (327 MHz) and NVSS (1.4 GHz) catalogs, we obtained (1) The median spectral index increases from amed --0.9 toαmed --0.8 (Svαvα), while S327 flux densities decrease from 0.1 Jy down to 25mJy. The median spectral indices nearly show no variation within the error bars when the flux density is larger than 0.1 Jy. (2) A dependence of the fraction of ultra-steep spectrum sources (USS, -1.5 which increases with decreasing flux densities. (3) The spectral flattening for faint sources (down to S327- 20mJy) with steep spectra (αwith luminosity rather than redshift according to the Condon' model. (4) A strong spectral selection effect occurs when spectral indices are calculated from samples with a large frequency separation.

关键词： radio continuum: general-methods: statistical - cosmology

Protruding Structure Buried in Radio Map by wavelet

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Chinese Physics Letters 2000年第5期17卷 388-389页

作者： CHEN Pu-Chun ZHANG Xi-Zhen XIANG Shou-Ping FENG Long-Long w.reich Astrophysical Center University of Science and Technology of ChinaHefei 230026 National Astronomical Observatories Beijing Astronomical Observatory Chinese Academy of SciencesBeijing 100012 Department of Industrial Automation Southwest Petroleum InstituteNanchong 637001 Max-Planck-Institute fur Radioastronomie Auf dem Hugel 6953121 BonnGermany

An efficient method to identify supernova remnants is provided,in order to iron out the great gap between the predicted number and the *** make an attempt to apply D4 wavelet to detect the useful structures buried in ... 详细信息

关键词： buried noise apply

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精神分析学批判

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Daubechies小波在射电成图降噪处理中的应用

1936年

作者： w.Jurinetz w.reich 卢心远译

来源：汇雅图书（南通市图书馆... 评论

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天文学报 2000年第3期41卷 327-332页

作者：陈普春张喜镇向守平冯珑珑 w.reich 中国科学技术大学天体物理中心合肥230026 中国科学院国家天文观测中心中国科学院北京天文台北京100012 MaxPlanckInstitutefrRadioastronomie

在超新星遗迹的认证中 ,如何有效去除观测资料中的干扰噪音 ,突出其中的有用信号 ,一直是实验工作者关注的焦点 .小波分析法是一种新近发展起来的新的时频分析方法 .与Fourier分析方法一样 ,任意的能量有限函数可以用小波正交基展开 .与... 详细信息

在超新星遗迹的认证中 ,如何有效去除观测资料中的干扰噪音 ,突出其中的有用信号 ,一直是实验工作者关注的焦点 .小波分析法是一种新近发展起来的新的时频分析方法 .与Fourier分析方法一样 ,任意的能量有限函数可以用小波正交基展开 .与Fourier正交基不同的是 ,小波正交基具有局域性好的特性 ,这为分离观测资料中的局部噪音 ,提供了一个十分有效的工具 .在利用Daubechies 4离散小波时 ,成功地去除了射电源成图中的干扰条纹 .结果表明 ,在降噪的同时 ,小波降噪法可以保留尽可能多的有用细节 .

关键词：图像处理 Daubechies小波射电图像降噪

A novel method for clustering cellular data to improve classification

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Neural Regeneration Research 2025年第9期20卷 2697-2705页

作者： Diek w.wheeler Giorgio A.Ascoli Center for Neural Informatics Structures&PlasticityKrasnow Institute for Advanced Study Bioengineering Department Volgenau School of Engineering George Mason University FairfaxVAUSA

Many fields,such as neuroscience,are experiencing the vast prolife ration of cellular data,underscoring the need fo r organizing and interpreting large datasets.A popular approach partitions data into manageable subsets via hierarchical clustering,but objective methods to determine the appropriate classification granularity are *** recently introduced a technique to systematically identify when to stop subdividing clusters based on the fundamental principle that cells must differ more between than within *** we present the corresponding protocol to classify cellular datasets by combining datadriven unsupervised hierarchical clustering with statistical *** general-purpose functions are applicable to any cellular dataset that can be organized as two-dimensional matrices of numerical values,including molecula r,physiological,and anatomical *** demonstrate the protocol using cellular data from the Janelia MouseLight project to chara cterize morphological aspects of neurons.

关键词： cellular data clustering dendrogram data classification Levene's one-tailed statistical test unsupervised hierarchical clustering

Genistein:a possible solution for the treatment of Alzheimer’s disease

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Neural Regeneration Research 2025年第10期20卷 2903-2905页

作者： Karolina Pierzynowska Bartosz Karaszewski Grzegorz węgrzyn Department of Molecular Biology University of GdanskGdanskPoland Gdansk Polandand Department of Adult NeurologyFaculty of MedicineMedical University of GdanskGdanskPoland

Neurodegenerative diseases are defined as disorders resulting from the slow and progressive loss of function and eventual death of neural cells that result from the primary pathology of nervous *** can lead to severe nervous system dysfunction,eventually affecting multiple organs and *** hundred neurodegenerative diseases have been described,and owing to their prevalence,severity.

关键词： organs Alzheimer death

Glia-to-neuron reprogramming to the rescue?

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Neural Regeneration Research 2025年第5期20卷 1395-1396页

作者： Jack w.Hickmott Cindi M.Morshead Department of Surgery University of TorontoTorontoONCanada Donnelly Centre for Cellular and Biomolecular Research TorontoONCanada Institute of Biomedical Engineering University of TorontoTorontoONCanada The KITE Research Institute Toronto Rehabilitation InstituteUniversity Health NetworkTorontoONCanada

Over the last two decades,the dogma that cell fate is immutable has been increasingly challenged,with important implications for regenerative *** brea kth rough discovery that induced pluripotent stem cells could be generated from adult mouse fibroblasts is powerful proof that cell fate can be *** exciting extension of the discovery of cell fate impermanence is the direct cellular reprogram ming hypothesis-that terminally differentiated cells can be reprogrammed into other adult cell fates without first passing through a stem cell state.

关键词： programming passing proof

The Galactic halo magnetic field revisited

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Research in Astronomy and Astrophysics 2010年第12期10卷 1287-1297页

作者： wolfgang reich Max-Planck-Institut für Radioastronomie Auf dem Hügel 69 53121 Bonn Germany

Recently, Sun et al. published new Galactic 3D-models of magnetic fields in the disk and halo of the Milky way and the distribution of cosmic-ray electron density by taking into account the thermal electron density model NE2001 by Cordes ＆ Lazio. The models successfully reproduce observed continuum and polarization all-sky maps and the distribution of rotation measures of extragalactic sources across the sky. However, the model parameters obtained for the Galactic halo, although reproducing the observations, seem physically unreasonable： the magnetic field needs to be significantly stronger in the Galactic halo than in the plane and the cosmic-ray distribution must be truncated at about 1 kpc to avoid excessive synchrotron emission from the halo. The reason for these unrealistic parameters was the low scale-height of the warm thermal gas of about 1 kpc adopted in the NE2001 model. However, this scale- height seemed reasonable and was well studied by numerous investigations. Recently, the scale-height of the warm gas in the Galaxy was revised by Gaensler et al. to about 1.8 kpc, by showing that the 1 kpc scale-height results from a systematic bias in the analysis of pulsar data. This implies a higher thermal electron density in the Galactic halo, which in turn reduces the halo magnetic field strength to account for the observed rotation measures of extragalactic sources. we slightly modified the NE2001 model according to the new scale-height and revised the Sun et al. model parameters accordingly： the strength of the regular halo magnetic field is now 2 μG or lower, and the physically unrealistic cutoff in z for the cosmic-ray electron density is removed. The simulations based on the revised 3D-models reproduce all-sky observations as before.

关键词： ISM: magnetic fields -- ISM: structure -- radio continuum: ISM

Distance management of inflammatory bowel disease:Systematic review and meta-analysis

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world Journal of Gastroenterology 2014年第3期20卷 829-842页

作者： Vivian w Huang Krista M reich Richard N Fedorak Division of Gastroenterology University of Alberta

AIM: To review the effectiveness of distance management methods in the management of adult inflammatory bowel disease (IBD) patients.

关键词： Telemanagement Telehealth Inflammatory bowel disease Distance management Self-management