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期刊论文 31

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2022 1

2020 3

2019 1

2018 1

2017 6

2016 3

2014 1

2012 2

2011 3

2010 1

2008 4

2005 1

2004 1

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关键词

功率谱密度 2

CCD影像 1

Chrestenson谱 1

MIMO雷达;波形设计;谱分解;分式二次约束二次规划 1

m值逻辑函数 1

三维 1

严格雪崩准则 1

光谱信息 1

光谱成像;计算成像;光谱仪 1

分子荧光光谱 1

分析滤波器;线性预测;窄带语音水印;通带激励替代;能量规范化;谱包络成形;合成滤波器 1

反射光谱 1

叶绿素荧光 1

多光谱 1

多光谱/高光谱视频采集;单次曝光;采样与重建 1

多变低水 1

天然溶解有机质 1

定量遥感 1

客运专线 1

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Spectral reflectance indices as proxies for yield potential and heat stress tolerance in spring wheat

Caiyun LIU, Francisco PINTO, C. Mariano COSSANI, Sivakumar SUKUMARAN, Matthew P. REYNOLDS

《农业科学与工程前沿(英文)》 2019年 第6卷 第3期   页码 296-308 doi: 10.15302/J-FASE-2019269

摘要:

The application of spectral reflectance indices (SRIs) as proxies to screen for yield potential (YP) and heat stress (HS) is emerging in crop breeding programs. Thus, a comparison of SRIs and their associations with grain yield (GY) under YP and HS conditions is important. In this study, we assessed the usefulness of 27 SRIs for indirect selection for agronomic traits by evaluating an elite spring wheat association mapping initiative (WAMI) population comprising 287 elite lines under YP and HS conditions. Genetic and phenotypic analysis identified 11 and 9 SRIs in different developmental stages as efficient indirect selection indices for yield in YP and HS conditions, respectively. We identified enhanced vegetation index (EVI) as the common SRI associated with GY under YP at booting, heading and late heading stages, whereas photochemical reflectance index (PRI) and normalized difference vegetation index (NDVI) were the common SRIs under booting and heading stages in HS. Genome-wide association study (GWAS) using 18704 single nucleotide polymorphisms (SNPs) from Illumina iSelect 90K identified 280 and 43 marker-trait associations for efficient SRIs at different developmental stages under YP and HS, respectively. Common genomic regions for multiple SRIs were identified in 14 regions in 9 chromosomes: 1B (60–62 cM), 3A (15, 85–90, 101–105 cM), 3B (132–134 cM), 4A (47–51 cM), 4B (71–75 cM), 5A (43–49, 56–60, 89–93 cM), 5B (124–125 cM), 6A (80–85 cM), and 6B (57–59, 71 cM). Among them, SNPs in chromosome 5A (89–93 cM) and 6A (80–85 cM) were co-located for yield and yield related traits. Overall, this study highlights the utility of SRIs as proxies for GY under YP and HS. High heritability estimates and identification of marker-trait associations indicate that SRIs are useful tools for understanding the genetic basis of agronomic and physiological traits.

关键词: genome-wide association study (GWAS)     heat tolerance     spectral reflectance     spring wheat    

低水多变环境下玉米叶片的光合与反射光谱特征

孙莉,苏根强,刘艳梅,赵闫闫,史刚荣

《中国工程科学》 2012年 第14卷 第3期   页码 70-75

摘要:

采用盆栽试验,以玉米品种苏玉19为试材,在每次复水第7天同时测定不同处理植株的生物量、根冠比、叶绿素荧光、气体交换以及光谱特征等指标。结果表明,持续干旱处理抑制植株生长,增加根冠比,并通过气孔限制和非气孔限制因素抑制光合作用。持续干旱处理幼苗的mSR705、chlNDI和REP均显著小于对照,但对SIPI的影响不显著。多变低水环境下玉米幼苗生长明显受到抑制,但根冠比、叶绿素荧光、气体交换以及光谱特征等指标与正常供水没有差异。可见,生物量分配、光合作用和光谱特征的维持可能是玉米适应多变低水环境的重要生理机制。

关键词: 玉米     多变低水     叶绿素荧光     气体交换     反射光谱    

Applying the spectral stochastic finite element method in multiple-random field RC structures

《结构与土木工程前沿(英文)》   页码 434-447 doi: 10.1007/s11709-022-0820-6

摘要: This paper uses the spectral stochastic finite element method (SSFEM) for analyzing reinforced concrete (RC) beam/slab problems. In doing so, it presents a new framework to study how the correlation length of a random field (RF) with uncertain parameters will affect modeling uncertainties and reliability evaluations. It considers: 1) different correlation lengths for uncertainty parameters, and 2) dead and live loads as well as the elasticity moduli of concrete and steel as a multi-dimensional RF in concrete structures. To show the SSFEM’s efficiency in the study of concrete structures and to evaluate the sensitivity of the correlation length effects in evaluating the reliability, two examples of RC beams and slabs have been investigated. According to the results, the RF correlation length is effective in modeling uncertainties and evaluating reliabilities; the longer the correlation length, the greater the dispersion range of the structure response and the higher the failure probability.

关键词: uncertainty     spectral stochastic finite element method     correlation length     reliability assessment     reinforced concrete beam/slab    

Fault feature extraction of planet gear in wind turbine gearbox based on spectral kurtosis and time wavelet

Yun KONG, Tianyang WANG, Zheng LI, Fulei CHU

《机械工程前沿(英文)》 2017年 第12卷 第3期   页码 406-419 doi: 10.1007/s11465-017-0419-0

摘要:

Planetary transmission plays a vital role in wind turbine drivetrains, and its fault diagnosis has been an important and challenging issue. Owing to the complicated and coupled vibration source, time-variant vibration transfer path, and heavy background noise masking effect, the vibration signal of planet gear in wind turbine gearboxes exhibits several unique characteristics: Complex frequency components, low signal-to-noise ratio, and weak fault feature. In this sense, the periodic impulsive components induced by a localized defect are hard to extract, and the fault detection of planet gear in wind turbines remains to be a challenging research work. Aiming to extract the fault feature of planet gear effectively, we propose a novel feature extraction method based on spectral kurtosis and time wavelet energy spectrum (SK-TWES) in the paper. Firstly, the spectral kurtosis (SK) and kurtogram of raw vibration signals are computed and exploited to select the optimal filtering parameter for the subsequent band-pass filtering. Then, the band-pass filtering is applied to extrude periodic transient impulses using the optimal frequency band in which the corresponding SK value is maximal. Finally, the time wavelet energy spectrum analysis is performed on the filtered signal, selecting Morlet wavelet as the mother wavelet which possesses a high similarity to the impulsive components. The experimental signals collected from the wind turbine gearbox test rig demonstrate that the proposed method is effective at the feature extraction and fault diagnosis for the planet gear with a localized defect.

关键词: wind turbine     planet gear fault     feature extraction     spectral kurtosis     time wavelet energy spectrum    

Application of spectral technology in flame measurement

Jiaxun LIU, Xiaoshu CAI, Zenghao ZHU, Huinan YANG

《能源前沿(英文)》 2014年 第8卷 第1期   页码 138-143 doi: 10.1007/s11708-013-0283-5

摘要: Spectral technology has become an important detection method due to its advantages such as non-intrusive measurement and on-line analysis. In this paper, two applications of spectral technology in thermal detection were proposed. First, a novel spectroscopic method based on Planck’s law for measurement of emissivity was introduced. The emissivity, obtained by comparing the radiation intensity of the blackbody which had the same temperature as the flame with the detected intensity of the flames, could be used for on-line measurements and had a relatively higher upper temperature limit. Then, a spectroscopic method for composition detection of blended fuels was proposed based on the emissivity measured. By comparing the spectra of blended fuels and single fuels, the ratio of single fuels of the blended fuel could be calculated. The measurement system proposed in this paper, which consists of a spectrometer and a computer, is very compact.

关键词: spectrum     emissivity measurement     component of fuel     near-infrared spectrometer    

Spectral element modeling based structure piezoelectric impedance computation and damage identification

Zhigang GUO, Zhi SUN

《结构与土木工程前沿(英文)》 2011年 第5卷 第4期   页码 458-464 doi: 10.1007/s11709-011-0133-7

摘要: This paper presents a numerical simulation study on electromechanical impedance technique for structural damage identification. The basic principle of impedance based damage detection is structural impedance will vary with the occurrence and development of structural damage, which can be measured from electromechanical admittance curves acquired from PZT patches. Therefore, structure damage can be identified from the electromechanical admittance measurements. In this study, a model based method that can identify both location and severity of structural damage through the minimization of the deviations between structural impedance curves and numerically computed response is developed. The numerical model is set up using the spectral element method, which is promised to be of high numerical efficiency and computational accuracy in the high frequency range. An optimization procedure is then formulated to estimate the property change of structural elements from the electric admittance measurement of PZT patches. A case study on a pin-pin bar is conducted to investigate the feasibility of the proposed method. The results show that the presented method can accurately identify bar damage location and severity even when the measurements are polluted by 5% noise.

关键词: PZT     piezoelectric impedance     optimization     spectral element     damage identification    

Nongray radiation from gas and soot mixtures in planar plates based on statistical narrow-band spectral

Huaqiang CHU, Qiang CHENG, Huaichun ZHOU, Fengshan LIU

《能源前沿(英文)》 2011年 第5卷 第2期   页码 149-158 doi: 10.1007/s11708-010-0124-8

摘要: The nongray behavior of combustion products plays an important role in various areas of engineering. Based on the statistical narrow-band (SNB) spectral model with an exponential-tailed inverse intensity distribution and the ray-tracing method, a comprehensive investigation of the influence of soot on nongray radiation from mixtures containing H O/N +soot, CO /N +soot, or H O/CO /N +soot was conducted in this paper. In combustion applications, radiation transfer is significantly enhanced by soot due to its spectrally continuous emission. The effect of soot volume fraction up to 1×10 on the source term, the narrow-band radiation intensities along a line-of-sight, and the net wall heat fluxes were investigated for a wide range of temperature. The effect of soot was significant and became increasingly drastic with the increase of soot loading.

关键词: soot     combustion     SNB model     nongray radiation    

Spectral characteristics of plant communities from salt marshes: A case study from Chongming Dongtan,

ZHANG Liquan, GAO Zhanguo, Armitage Richard, Kent Martin

《环境科学与工程前沿(英文)》 2008年 第2卷 第2期   页码 187-197 doi: 10.1007/s11783-008-0004-1

摘要: The spectral reflectance of recently formed salt marshes at the mouth of the Yangtze River, which are undergoing invasion by , were assessed to determine the potential utility of remotely sensed data in assessing future invasion and changes in species composition. Following a review of published research on remote sensing of salt marshes, 53 locations along three transects were sampled for paired data on plant species composition and spectral reflectance using a FieldSpec Pro JR Field Portable Spectroradiometer. Spectral data were processed concerning reflectance, and the averaged reflectance values for each sample were re-analysed to correspond to a 12-waveband bandset of the Compact Airborne Spectral Imager. The spectral data were summarised using principal components analysis (PCA) and the relationships between the vegetation composition, and the PCA axes of spectral data were examined. The first PCA axis of the reflectance data showed a strong correlation with variability in near infrared reflectance and ‘brightness’, while the second axis was correlated with visible reflectance and ‘greenness’. Total vegetation cover, vegetation height, and mudflat cover were all significantly related to the first axis. The implications of this in terms of the ability of remote sensing to distinguish the various salt marsh species and in particular the invasive species were discussed. Major differences in species with various physiognomies could be recognised but problems occurred in separating early colonising from other species at that stage. Further work using multi-seasonal hyperspectral data might assist in solving these problems.

关键词: Spectral     multi-seasonal hyperspectral     invasive     JR     re-analysed    

一种基于锚点的谱聚类方法 None

Qin ZHANG, Guo-qiang ZHONG, Jun-yu DONG

《信息与电子工程前沿(英文)》 2018年 第19卷 第11期   页码 1385-1396 doi: 10.1631/FITEE.1700262

摘要: 为解决该问题,提出一种新的基于锚点谱聚类方法(anchor-based spectral clustering,ASC)。将该方法与经典谱聚类方法和两种最新谱聚类加速方法,即能量迭代聚类(power iteration clustering,PIC)和基于地标聚类(landmark-based spectral clustering

关键词: 聚类;谱聚类;图拉普拉斯;锚点    

Synthesis and characterization of macromolecular surface modifier PP--PEG for polypropylene

CHEN Hanjia, SHI Xuhua, ZHU Yafei, ZHANG Yi, XU Jiarui

《化学科学与工程前沿(英文)》 2008年 第2卷 第1期   页码 102-108 doi: 10.1007/s11705-008-0018-z

摘要: A novel macromolecular surface modifier, polypropylene-grafted-poly(ethylene glycol) copolymer (PP--PEG), was synthesized by coupling polypropylene containing maleic anhydride with monohydroxyl-terminated poly(ethylene glycol). The effects of the reaction condition on the graft reactions were studied. The copolymers were characterized by IR, H NMR, thermogravimetry (TG) and differential scanning calorimetry (DSC). The results indicated that the graft reactions were hindered by increasing the molecular weight of PP or PEG. The graft copolymer was found to have a higher initial thermal degradation temperature and lower crystallization capacity as compared with pure PP, and the side chain of PEG hindered the PP chain from forming a perfect ? crystal. The thermal stability of PP--PEG decreased with the increasing content or molecular weight of PEG. The copolymers were blended with polypropylene to modify the surface hydrophilicity of the products. The results of attenuated total reflectance FTIR spectroscopy (ATR-FTIR) showed that PP--PEG could diffuse preferably onto the surface of the blends and be suitable as an effectual macromolecular surface modifier for PP.

关键词: polypropylene     crystallization capacity     attenuated     hydrophilicity     reflectance    

焊接电弧光谱信息测控技术及其应用

李俊岳,杨运强,李桓,张晓囡,杨立军

《中国工程科学》 2001年 第3卷 第7期   页码 21-29

摘要:

焊接电弧中含有丰富的光谱信息,利用这些信息对焊接电弧这一复杂的物理现象进行测试(或称诊断)和控制,是提高和发展焊接技术的一种非常有效的方法,具有重要的理论和实际意义。文章论述了这方面 研究的进展,阐明了电弧光谱信息的测控原理,介绍了电弧光谱信息在电弧诊断,电弧气氛监控,弧焊区成像,特别是近年来在脉冲MIG焊熔滴过渡控制等方面的应用情况。同时,还介绍了这一技术在等离子体现象中的一些重要应用,并总结出几点基本看法,指出了它的发展方向。

关键词: 光谱信息     焊接电弧     等离子体     诊断     自动控制    

脉冲MIG焊熔滴过渡光谱信息的研究

李俊岳,杨立军,胡胜钢,李桓,柳刚

《中国工程科学》 2000年 第2卷 第7期   页码 79-86

摘要:

采用焊接电弧光谱检测装置,对脉冲MIG焊熔滴过渡的光谱信息进行了研究,结果表明,电弧光谱信息可以很好地反映脉冲MIG焊的熔滴过渡;发现了多种熔滴过渡的光谱信息模式,这些模式可反映1峰0基、1峰1基等各种形式的熔滴过渡,特别是可以对脉冲峰值期间的多滴喷射过渡作出清晰的反映;信号波形的脉动幅值大,脉宽较宽,抗干扰能力强,容易识别,信号品质优越。这些结果为脉冲MIG焊熔滴过渡的光谱实时控制奠定了良好基础,为脉冲MIG焊的控制开辟了一条新途径。

关键词: 电弧光谱信息     脉冲MIG焊     熔滴过渡     过渡模式    

Preparation and gaseous photocatalytic activity of smooth potassium dititanate film

QIAN Qinghua, HU Yuyan, WEN Gaofei, FENG Xin, LU Xiao-hua

《化学科学与工程前沿(英文)》 2008年 第2卷 第3期   页码 308-314 doi: 10.1007/s11705-008-0047-7

摘要: A new smooth potassium dititanate film was prepared by sol-gel method and characterized by thermogravimetry (TG) and differential scanning calorimetry (DSC), X-ray diffraction (XRD), atomic force microscopy (AFM), UV-Visible diffuse reflectance and Raman spectroscopy. The gaseous photocatalytic activity of smooth KTiO films was studied using contact angle analysis from the photocatalytic decomposition of octadecyltrichlorosilane (OTS) based self-assembled monolayers (SAMs) formed on KTiO films. The photocurrent response of the film was determined by an electrochemical method. It was shown that the films were smooth, compact, and transparent when formed on glass. Compared with TiO film, the KTiO film showed wide absorption in the ultraviolet and visible region. It was found that the monolayers on KTiO decomposed much faster than those on TiO under UV irradiation of 254 nm in air. The film also exhibited a stronger photoresponse and a more stable anodic photocurrent. The KTiO film efficiently decomposes the alkylsiloxane monolayers under UV irradiation in air and it was found to be a good photocatalyst for gaseous organic pollutant treatment.

关键词: reflectance     UV-Visible     photocurrent     irradiation     scanning calorimetry    

A fast antibiotic detection method for simplified pretreatment through spectra-based machine learning

《环境科学与工程前沿(英文)》 2022年 第16卷 第3期 doi: 10.1007/s11783-021-1472-9

摘要:

• A spectral machine learning approach is proposed for predicting mixed antibiotic.

关键词: Antibiotic contamination     Spectral detection     Machine learning    

Three-dimensional fluorescence spectral characterization of soil dissolved organic matters in the fluctuating

Fang FANG, Yan YANG, Jinsong GUO, Hong ZHOU, Chuan FU, Zhe LI

《环境科学与工程前沿(英文)》 2011年 第5卷 第3期   页码 426-434 doi: 10.1007/s11783-010-0264-4

摘要: Three-dimensional fluorescence spectroscopy was used to investigate the fluorescent properties of soil dissolved organic matter (DOM) in the water-level-fluctuation zone (WLFZ) of Kai County, Three Gorges Reservoir (TGR). Most of the soil DOM analyzed in this study was found to contain four fluorescence peaks. Peaks A and C represent humic-like fluorescence, whereas peaks B and D represent tryptophan-like fluorescence. Peaks E and F, which represent tyrosine-like fluorescence, only appeared in certain soils. Soil humus was the main source of DOM in soil, and higher concentration of soil DOM was found in the exposed soil than submerged soil. Compared to the peaks A and B, the fluorescence intensities of peaks C and D were strongly influenced by the fluctuating water level. Analysis of fluorescence intensities of different peaks in soil DOM showed that WLFZ soil was not contaminated significantly. Soil DOM contained at least two types of humic-like fluorescence groups and two types of protein-like fluorescence groups. The proportion of the content of peak A in soil organic matter was quite stable. The soil DOM in exposed soil had relatively high humification and aromaticity, and periodic submerging and exposure of soil had an impact on the humification of soil DOM.

关键词: water-level-fluctuation zone (WLFZ)     soil     dissolved organic matter (DOM)     three-dimensional fluorescence spectra    

标题 作者 时间 类型 操作

Spectral reflectance indices as proxies for yield potential and heat stress tolerance in spring wheat

Caiyun LIU, Francisco PINTO, C. Mariano COSSANI, Sivakumar SUKUMARAN, Matthew P. REYNOLDS

期刊论文

低水多变环境下玉米叶片的光合与反射光谱特征

孙莉,苏根强,刘艳梅,赵闫闫,史刚荣

期刊论文

Applying the spectral stochastic finite element method in multiple-random field RC structures

期刊论文

Fault feature extraction of planet gear in wind turbine gearbox based on spectral kurtosis and time wavelet

Yun KONG, Tianyang WANG, Zheng LI, Fulei CHU

期刊论文

Application of spectral technology in flame measurement

Jiaxun LIU, Xiaoshu CAI, Zenghao ZHU, Huinan YANG

期刊论文

Spectral element modeling based structure piezoelectric impedance computation and damage identification

Zhigang GUO, Zhi SUN

期刊论文

Nongray radiation from gas and soot mixtures in planar plates based on statistical narrow-band spectral

Huaqiang CHU, Qiang CHENG, Huaichun ZHOU, Fengshan LIU

期刊论文

Spectral characteristics of plant communities from salt marshes: A case study from Chongming Dongtan,

ZHANG Liquan, GAO Zhanguo, Armitage Richard, Kent Martin

期刊论文

一种基于锚点的谱聚类方法

Qin ZHANG, Guo-qiang ZHONG, Jun-yu DONG

期刊论文

Synthesis and characterization of macromolecular surface modifier PP--PEG for polypropylene

CHEN Hanjia, SHI Xuhua, ZHU Yafei, ZHANG Yi, XU Jiarui

期刊论文

焊接电弧光谱信息测控技术及其应用

李俊岳,杨运强,李桓,张晓囡,杨立军

期刊论文

脉冲MIG焊熔滴过渡光谱信息的研究

李俊岳,杨立军,胡胜钢,李桓,柳刚

期刊论文

Preparation and gaseous photocatalytic activity of smooth potassium dititanate film

QIAN Qinghua, HU Yuyan, WEN Gaofei, FENG Xin, LU Xiao-hua

期刊论文

A fast antibiotic detection method for simplified pretreatment through spectra-based machine learning

期刊论文

Three-dimensional fluorescence spectral characterization of soil dissolved organic matters in the fluctuating

Fang FANG, Yan YANG, Jinsong GUO, Hong ZHOU, Chuan FU, Zhe LI

期刊论文