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Automated estimation of stellar fundamental parameters from low resolution spectra: the PLS method

Research in Astronomy and Astrophysics 2009年第6期9卷 712-724页

作者： jian-Nan zhang A-li Luo Yong-Heng Zhao National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China

PLS （Partial Least Squares regression） is introduced into an automatic estimation of fundamental stellar spectral parameters. It extracts the most correlative spectral component to the parameters （Teff, log g and [Fe/H]）, and sets up a linear regression function from spectra to the corresponding parameters. Considering the properties of stellar spectra and the PLS algorithm, we present a piecewise PLS regression method for estimation of stellar parameters, which is composed of one PLS model for Teff, and seven PLS models for log g and [Fe/H] estimation. Its performance is investigated by large experiments on flux calibrated spectra and continuum normalized spectra at different signal-to-noise ratios （SNRs） and resolutions. The results show that the piecewise PLS method is robust for spectra at the medium resolution of 0.23 nm. For low resolution 0.5 nm and 1 nm spectra, it achieves competitive results at higher SNR. Experiments using ELODIE spectra of 0.23 nm resolution illustrate that our piecewise PLS models trained with MILES spectra are efficient for O ～ G stars： for flux calibrated spectra, the systematic offsets are 3.8%, 0.14 dex, and -0.09 dex for Teff, log g and [Fe/H], with error scatters of 5.2%, 0.44 dex and 0.38 dex, respectively; for continuum normalized spectra, the systematic offsets are 3.8%, 0.12dex, and -0.13 dex for Teff, log g and [Fe/H], with error scatters of 5.2%, 0.49 dex and 0.41 dex, respectively. The PLS method is rapid, easy to use and does not rely as strongly on the tightness of a parameter grid of templates to reach high precision as Artificial Neural Networks or minimum distance methods do.

关键词： methods data analysis -- methods statistical -- stars fundamental param- eters (classification, temperatures, metallicity) -- techniques spectroscopic -- surveys

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Shoot Apex Demand Determines Assimilate and Nutrients Partitioning and Nutrient-uptake Rate in Tobacco Plants

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Journal of Integrative Plant Biology 2007年第11期49卷 1654-1661页

作者： Huai-Yu Yang Chun-jian li Fu-Suo zhang The Key Laboratory of Plant Nutrition Ministry of Agriculture Key Laboratory of Plant-Soil Interactions Ministry of Education Department of Plant Nutrition China Agricultural University Beijing 100094 China

Our previous experiment revealed that apex-removed plants have larger root systems but a lower K＋-uptake rates than intact tobacco plants. Since the apex is not only a center of growth and metabolism, but also an important place of auxin synthesis and export, the aims of this study were to distinguish whether the apex demand or auxin synthesized in the apex regulates assimilate and nutrients partitioning within plant, and to explain the reason for the lower K＋-uptake rate of the apex-removed plant. In comparison with the control plant, covering the shoot apex with a black transparent plastic bag reduced net increases in dry matter and nutrients; however, the distribution of the dry matter and nutrients between shoot and roots and nutrient-uptake rates were not changed. Removal of the shoot apex shifted the dry mass and nutrients distributions to roots, and reduced the rate of nutrient uptake. Application of 1-naphthylacetic acid （NAA） could partly replace the role of the removed apex, stimulated assimilate and nutrient deposition into the treated tissue, and enhanced the reduced plasma membrane ATPase activity of roots to the control level. However, treatment of the apex-removed plants with NAA could not rescue the reduced nutrient uptake rate and the shifted assimilates and nutrients partitioning caused by excision of the apex. Higher nutrient uptake rate of the intact plants could not be explained by root growth parameters, such as total root surface area and number of root tips. The results from the present study indicate that strong apex demand determined assimilates and nutrients partitioning and nutrient-uptake rate in tobacco （Nicotiana tabacum） plants.

关键词： assimilate and nutrient partitioning auxin nutrient uptake removal of the shoot apex shoot apex demand tobacco (Nicotiana tabacum).

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Dioxygen Affinities and Catalytic Oxidation Performance of Cobalt (Ⅱ)Complexes with N—Aryl Hydroxamic Acid

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Chinese Chemical Letters 2003年第6期14卷 627-630页

作者： Chun Chun zhang Wei ZENG jian zhang li Sheng Ying QIN Department of Chemistry Sichuan UniversityChengdu 610064

The oxygenation of cobalt (II) hydroxamates (CoL2) and its catalytic performance in oxidation of p-xylene to p-toluic acid (PTA) were examined. The effects of X and Y bonded to hydroxamate group on dioxygen affinitie... 详细信息

关键词： Cobalt (II) hydroxamates dioxygen affinities catalytic oxidation p-xylene.

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An Open Access 4×4 MIMO Testbed and its Validation with an IEEE 802,11n WLAN System

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China Communications 2014年第A01期11卷 64-71页

作者： SUN jian li Fudong zhang Haixia jianG Mingyan YUAN Dongfeng SchoolofInformationScienceandEngineering ShandongUniversityJinan250100ShandongChina

Multiple-Input Multiple-Output （MIMO） and Orthogonal Frequency Division Multiplexing （OFDM） have been widely accepted as key techniques of the current and future wireless communication systems. In this paper, an open access MIMO testbed is presented, on which the researchers can demonstrate and evaluate their baseband algorithms over the real wireless channel, without knowing much details about the hardware of the testbed. Moreover, an IEEE 802.11n transmission scheme is implemented as a design example to validate this testbed as well as demonstrate the transmission characteristics of MIMO-OFDM.

关键词： open access testbed MIMO MIMO-OFDM IEEE 802.1 ln receiver algorithms

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AI-2 Key Enzyme S-Ribosylhomocysteinase from Strain Klebsiella pneumoniae CICC 10011 Producing 2,3-Butanediol

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Chemical Research in Chinese Universities 2011年第2期27卷 273-276页

作者： DAI jian-ying zhang li-fu XIU Zhi-long School of life Science and Biotechnology Dalian University of Technology Dalian 116024 P. R. China

S-Ribosylhomocysteinase（LuxS） is the key enzyme in the synthetic pathway of a quorum sensing autoinducer AI-2. LuxS from a 2,3-butanediol produced strain Klebisella pneumoniae CICC 10011 was cloned and characterized. The luxS gene is composed of 540 bp with 172 amino acids encoded. The Km value for S-ribosylhomo- cysteine（SRH） was （27±1） umol/L, kcat was （0.112±0.004） s-1 and kcat/Km was 4.4×103 L umol-1·s-1 at 25 ℃. LuxS was activated by divalent metal ions, the highest activity was detected with Co2＋ form, followed by Mg2＋, Ba2＋, Mn2＋, Fe2＋ and Ca2＋, and activation constant for Co2＋ is （16±2） umol/L.

关键词： S-Ribosylhomocysteinase(LuxS) Kinetics Characterization Klebsiellapneumoniae

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Synthesis and Crystal Structure of [Cd(NBA)(μ_3-OH)(4,4′-bipy)_(1/2)]_n

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Chinese Journal of Structural Chemistry 2007年第8期26卷 917-919页

作者： SHEN Yi-Cheng zhang jian li Zhao-Ji zhang Lei YIN Pei-Xiu YAO Yuan-Gen State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter The Chinese Academy of Sciences Fuzhou Fujian 350002 China

A new cadmium polymer [Cd（NBA）（μ3-OH）（4,4＇-bipy）1/2]n 1 （NBA=m-nitrobenzoic acid and 4,4＇-bipy=4,4-bipyridine） has been synthesized by hydrothermal reaction. Its structure was determined by single-crystal X-ray diffraction method, and characterized by elemental analysis and IR spectrum. The crystal is of monoclinic, space group C2/c, with a=15.6912（9）, b=25.9394（15）, c=6.7332（4）A, β=114.7700（10）°, V=2488.4（3）A^3, C12H9CdN2O5, Mr=373.61, Z=8, Dc=1.995 g/cm^3,μ=1.776 mm^-1, F（000）=1464, R=0.0411 and wR=0.1128 for 2130 observed reflections （I 〉 2σ（I））.X-ray diffraction studies reveal that the compound features a layered structure, in which 4,4＇-bipy ligands bridge Z type of double chains [Cd（μ3-OH）]n and NBA ligands locate at the two sides of the layer. The π-π interactions between the benzene rings of NBA ligands of two adjacent layers lead to the 3D framework.

关键词： cadmium polymer 4 4'-bipyridine m-nitrobenzoic acid crystal structure

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Preliminary study of the effects of EVA coupling agents on properties of wood-plastic composites

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Forestry Studies in China 2010年第2期12卷 90-94页

作者： li Dong-fang li li li jian-zhang College of Materials Science and Technology Beijing Forestry University Beijing 100083 P. R. China

As a hot-melt adhesive, ethylene-vinyl-acetate （EVA） has been used in many industrial applications. But studies of the application of EVA in wood-plastic composites （WPC） are relatively few, so we have investigated the proposition of whether EVA is a suitable coupling agent for WPC or not. The results show that EVA with 8% VA is not a suitable coupling agent, because it reduces the mechanical properties of WPC without any significant effect on its physical properties. With an increase in the amount of wood powder, the mechanical properties of WPC decrease and the ability of water absorption of WPC increases.

关键词： wood-plastic composites ethylene-vinyl-acetate coupling agent property

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Identification of potential oxidative stress biomarkers for spinal cord injury in erythrocytes using mass spectrometry

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Neural Regeneration Research 2021年第7期16卷 1294-1301页

作者： li-jian zhang Yao Chen Lu-Xuan Wang Xiao-Qing Zhuang He-Chun Xia School of Clinical Medicine Ningxia Medical UniversityYinchuanNingxia Hui Autonomous RegionChina Department of Neurosurgery General Hospital of Ningxia Medical UniversityYinchuanNingxia Hui Autonomous RegionChina Ningxia Human Stem Cell Research Institute General Hospital of Ningxia Medical UniversityYinchuanNingxia Hui Autonomous RegionChina Department of Nuclear Medicine General Hospital of Ningxia Medical UniversityYinchuanNingxia Hui Autonomous RegionChina

Oxidative stress is a hallmark of secondary injury associated with spinal cord *** stable and specific oxidative biomarkers is of important significance for studying spinal cord injury-associated secondary *** erythrocytes do not contain nuclei and mitochondria and cannot be transcribed and ***, mature erythrocytes are highly sensitive to oxidative stress and may become a valuable *** the present study, we revealed the proteome dynamics of protein expression in erythrocytes of beagle dogs in the acute and subacute phases of spinal cord injury using mass spectrometry-based *** found 26 proteins that were differentially expressed in the acute(0–3 days) and subacute(7–21 days) phases of spinal cord *** analysis revealed that these differentially expressed proteins were involved in glutathione metabolism, lipid metabolism, and pentose phosphate and other oxidative stress *** blot assays validated the differential expression of glutathione synthetase, transaldolase, and *** result was consistent with mass spectrometry results, suggesting that erythrocytes can be used as a novel sample source of biological markers of oxidative stress in spinal cord *** synthetase, transaldolase, and myeloperoxidase sourced from erythrocytes are potential biomarkers of oxidative stress after spinal cord *** study was approved by the Experimental Animal Centre of Ningxia Medical University, China(approval No.2017-073) on February 13, 2017.

关键词： acute phase bioinformatic analysis biomarkers central nervous system dog erythrocytes mass spectrometry oxidative stress peripheral blood spinal cord injury subacute phase

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Gene and protein expression profiles of olfactory ensheathing cells from olfactory bulb versus olfactory mucosa

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Neural Regeneration Research 2022年第2期17卷 440-449页

作者： Yuan-Xiang Lan Ping Yang Zhong Zeng Neeraj Yadav li-jian zhang li-Bin Wang He-Chun Xia School of Clinical Medicine Ningxia Medical UniversityYinchuanNingxia Hui Autonomous RegionChina Ningxia Human Stem Cell Institute General Hospital of Ningxia Medical UniversityYinchuanNingxia Hui Autonomous RegionChina Department of Neurosurgery General Hospital of Ningxia Medical UniversityYinchuanNingxia Hui Autonomous RegionChina Clinical Laboratory Center General Hospital of Ningxia Medical UniversityYinchuanNingxia Hui Autonomous RegionChina School of International Education Ningxia Medical UniversityYinchuanNingxia Hui Autonomous RegionChina Biochip Research Center General Hospital of Ningxia Medical UniversityYinchuanNingxia Hui Autonomous RegionChina

Olfactory ensheathing cells(OECs) from the olfactory bulb(OB) and the olfactory mucosa(OM) have the capacity to repair nerve injury. However, the difference in the therapeutic effect between OB-derived OECs and OM-derived OECs remains unclear. In this study, we extracted OECs from OB and OM and compared the gene and protein expression profiles of the cells using transcriptomics and non-quantitative proteomics techniques. The results revealed that both OB-derived OECs and OM-derived OECs highly expressed genes and proteins that regulate cell growth, proliferation, apoptosis and vascular endothelial cell regeneration. The differentially expressed genes and proteins of OB-derived OECs play a key role in regulation of nerve regeneration and axon regeneration and extension, transmission of nerve impulses and response to axon injury. The differentially expressed genes and proteins of OM-derived OECs mainly participate in the positive regulation of inflammatory response, defense response, cytokine binding, cell migration and wound healing. These findings suggest that differentially expressed genes and proteins may explain why OB-derived OECs and OM-derived OECs exhibit different therapeutic roles. This study was approved by the Animal Ethics Committee of the General Hospital of Ningxia Medical University(approval No. 2017-073) on February 13, 2017.

关键词： biological process cellular component gene Gene Ontology Kyoto Encyclopedia of Genes and Genomes molecular function olfactory bulb olfactory ensheathing cells olfactory mucosa protein

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Upconversion Luminescence from Ho3＋ and Yb3＋ Codoped α-NaYF4 Single Crystals

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Chinese Journal of Chemical Physics 2015年第3期28卷 351-354,I0002页

作者： Jia-zhong zhang Hai-ping Xia Shuo Yang Yong-zhang jiang Xue-mei Gu jian-li zhang Hao-chuan jiang Bao-jiu Chen Key laboratory of Photoelectronic Materials Ningbo University Ningbo 315211 China Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Ningbo 315211 China Department of Physics Dalian Maritime University Dalian 116026 China

The Ho3＋/yb3＋ co-doped a-NaYF4 single crystal was grown successfully for the first time by a modified Bridgman method in which KF was used as assisting flux and a large temperature gradient （70-90℃ /cm） of solid-liquid interface was adopted. Upconversion emissions at green -544 nm, red -657 and -751 nm were obtained under 980 nm laser diode excitation. The intensity at -544 nm was much stronger than those of -657 and -751 nm. The mechanisms of the upconversion emissions were investigated by studying the relationship between the upconversion intensity and pump power. The optimized Yb3＋ concentration was about 8.08moi% when Ho3＋ concentration was hold at about 1.0mol%. The results showed that Ho3＋/yb3＋ doped α-NaYF4 single crystal was a possible candidate upconversion material for the green solid-state laser.

关键词： Ho3+/yb3+ a-NaYF4 single crystal Fluorescent intensity Upconversion

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