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Chinese Journal of Electronics 2014年第2期23卷 361-365页

作者： YIN Hongtao fu Ping SUN zhen Automatic Test and Control Institute Harbin Institute of Technology

Discrete cosine transform(DCT) is an effective method to extract proper features for face recognition. Discrete cosine transform can only map the resource data to another data field instead of compress *** to select the DCT coefficients that are most effective for classification is an important problem. This paper proposes a novel method to search the best discriminant combination of DCT coefficients. A feature selection algorithm according to the separability criterion is used to preselect the DCT coefficients, and then follows a search algorithm based on binary particle swarm optimization and support vector machine to find an optimal combination of the DCT coefficient. The performance of the algorithm is assessed by computing the recognition rate and the number of selected features on ORL database and Cropped Yale database.

关键词： Separability criterion Binary particle swarm optimization Support vector machine Face recognition Feature selection

Natural variation and evolutionary dynamics of transposable elements in Brassica oleracea based on next-generation sequencing data

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Horticulture Research 2020年第1期7卷 990-1001页

作者： zhen Liu Miao Fan Er-Kui Yue Yu Li Ruo-fu Tao Hai-ming Xu ming-Hua Duan Jian-Hong Xu Institute of Crop Science Zhejiang Key Laboratory of Crop GermplasmZhejiang University310058 HangzhouPeople’s Republic of China Zhejiang zhengjingyuan Pharmacy Chain Co. Ltd.&Hangzhou Zhengcaiyuan Pharmaceutical Co.Ltd.310021 HangzhouPeople’s Republic of China

Brassica oleracea comprises various economically important vegetables and presents extremely diverse morphological *** provide a rich source of nutrition for human health and have been used as a model system for studying *** elements(TEs)account for nearly 40%of the *** genome and contribute greatly to genetic diversity and genome *** the proliferation of TEs has led to a large expansion of the *** genome,little is known about the population dynamics and evolutionary activity of TEs.A comprehensive mobilome profile of 45,737 TE loci was obtained from resequencing data from 121 diverse accessions across nine *** *** 70%(32,195)of the loci showed insertion polymorphisms between or within *** particular,up to 1221 loci were differentially fixed among *** analysis revealed that the distribution of the population frequency of TE loci was highly variable across different TE superfamilies and families,implying a diverse expansion history during host genome *** findings provide better insight into the evolutionary dynamics and genetic diversity of *** genomes and will potentially serve as a valuable resource for molecular markers and association studies between TE-based genomic variations and morphotype-specific phenotypic differentiation.

关键词： evolutionary dynamics elements

Design of non-polarizing thin film edge filters

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第6期7卷 1037-1040页

作者： GU Pei-fu zhenG zhen-rong State Key Laboratory of Modern Optical Instrumentation Zhejiang University Hangzhou 310027 China

The separation between s- and p-polarization components invariably affects thin film edge filters used for tilted incidence and is a difficult problem for many applications, especially for optical communication. This paper presents a novel design method to obtain edge filters with non-polarization at incidence angle of 45°. The polarization separation at 50% trans-mittance for a long-wave-pass filter and a short-wave-pass filter is 0.3 nm and 0.1 nm respectively. The design method is based on a broadband Fabry-Perot thin-film interference filter in which the higher or lower interference band at both sides of the main transmittance peak can be used for initial design of long-wave-pass filter or short-wave-pass filter and then can be refined to reduce the transmittance ripples. The spacer 2H2L2H or 2L2H2L of the filter is usually taken. Moreover, the method for expanding the bandwidth of rejection and transmission is explained. The bandwidth of 200 nm for both rejection region and transmission band is obtained at wavelength 1550 nm. In this way, the long-wave-pass and short-wave-pass edge filters with zero separation between two polarization components can easily be fabricated.

关键词： Thin film optics Interference edge filters Non-polarization design

Clustering Property of Wolf-Rayet Galaxies in the SDSS

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Chinese Journal of Astronomy and Astrophysics 2008年第2期8卷 211-218页

作者： Wei Zhang Xu Kong fu-zhen Cheng Center for Astrophysics University of Science and Technology of China Hefei 230026

We have analysed, for the first time, the clustering properties of Wolf-Rayet （W-R） galaxies, using a large sample of 846 W-R galaxies selected from the Data Release 4 （DR4） of the Sloan Digital Sky Survey （SDSS）. We compute the cross-correlation function between W- R galaxies and a reference sample of galaxies drawn from the DR4. We compare the function to the results for control samples of non-W-R star-forming galaxies that are matched closely in redshift, luminosity, concentration, 4000-A break strength and specific star formation rate （SSFR）. On scales larger than a few Mpc, W-R galaxies have almost the same clustering amplitude as the control samples, indicating that W-R galaxies and non-W-R control galaxies populate dark matter haloes of similar masses. On scales between 0.1-1 h^-1 Mpc, W-R galaxies are less clustered than the control samples, and the size of the difference depends on the SSFR. Based on both observational and theoretical considerations, we speculate that this negative bias can be interpreted by W-R galaxies residing preferentially at the centers of their dark matter haloes. We examine the distribution of W-R galaxies more closely using the SDSS galaxy group catalogue of Yang et al., and find that -82% of our W-R galaxies are the central galaxies of groups, compared to -74% for the corresponding control galaxies. We find that W-R galaxies are hosted, on average, by dark matter haloes of masses of 10^12.3M⊙, compared to 10^12.1M⊙ for centrally-located W-R galaxies and 10^12.7M⊙ for satellite ones. We would like to point out that this finding, which provides a direct observational support to our conjecture, is really very crude due to the small number of W-R galaxies and the incompleteness of the group catalogue, and needs more work in future with larger samples.

关键词： galaxies: distances and redshifts -- galaxies: starburst -- stars: Wolf-Rayet

Co-thermal in-situ reduction of inorganic carbonates to reduce carbon-dioxide emission

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Science China Chemistry 2023年第4期66卷 1201-1210页

作者： zhen Xue Jingyi Guo Shasha Wu Wenfu Xie Yujing fu Xiaojie Zhao Kui Fan ming Xu Hong Yan mingfei Shao Xue Duan State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China

Thermal decomposition of inorganic metal carbonates is the main path to prepare metal oxides;nonetheless,it is always accompanied by the emission of large amounts of CO_(2) as one of the gas *** study reports a concept of co-thermal insitu reduction of inorganic carbonates by using the energy released by carbonate decomposition under pure hydrogen atmosphere,which reduces the decarboxylation temperature and significantly inhibits the CO_(2) emissions.A combination of hydrogen–deuterium exchange,isotope experiment,and density functional theory calculations demonstrates that the CO results from the selective cleavage of Ca–O bonds at the surface of CaCO_(3) via the direct hydrogenation mechanism at relatively low ***,it undergoes the reverse water–gas shift reaction path at high temperature,i.e.,CO being produced by the reduction of CO_(2) released by the decomposition of *** study sheds light on the potential of green hydrogen technology for inorganic carbonate valorization toward high value-added products,which can facilitate the large-scale industrial applications.

关键词： inorganic carbonate co-thermal in-situ reduction carbon dioxide emission reduction carbon monoxide

Experimental Quantum Key Distribution over 14.8 km in a Special Optical Fibre

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Chinese Physics Letters 2003年第5期20卷 608-610页

作者： GUIYou-zhen HANzheng-fu MOXiao-Fan GUOGuang-Can KeyLaboratoryofQuantumInformaiton UniversityofScienceandTechnologyofChinaChineseAcademyofSciencesHefei230026

We present an experimental set-up for quantum key distribution in a special optical fibre at the wavelength of 850nm. The system employs the BB84 protocol to establish a secret key between Alice and Bob over 14.8km. The key is encoded in the phase of very weak laser of average photon number 0.11per pulse. The measured error rate is lower than 10%.

关键词：光学纤维量子通信编码量子传输光脉冲激光传输

Influence of Oxide Morphologies on Galvanizability of Third Generation Automotive Steel

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Journal of Iron and Steel Research International 2014年第11期21卷 1059-1064页

作者： She-ming JIANG Shi-jie FENG Xun-hua YUAN Yuan-peng LI zhen-hua LI Qi-fu ZHANG National Engineering Laboratory of Advanced Coating Technology for Metal Materials Central Iron and Steel Research Institute Faculty of Material Science and Engineering Kunming University of Science and Technology

Focusing on improving the galvanizability of the third generation automotive steel, the effect of surface ox ide morphologies on the galvanizability was studied. The results show that the surface oxide types of sample steels by X ray photoelectron spectroscopy （XPS） analysis after annealing in different conditions are the same. Only MnO, MnO2 and Cr2O3 were detected and no complex oxide exists on the surface. Morphologies of surface oxides can greatly influence the galvanizability of the third generation automotive steel. Nodule-like oxide surface can contribute to better wettability and inhibition layer than vitreous film like oxide surface. Galvanized panels of nodule-like oxide surface steels only show pinhole sized bare spots, while panels galvanized from vitreous film-like oxide surface steels reveal larger areas of bare spots and uncoated areas. Inhibition layer observed in galvanized panels of nodule-like oxide surface steels is compact but not homogeneous; some inhibition layer grains are fine, and others are coarse, while the inhibition layer grains of panels galvanized from vitreous film-like oxide surface steels have a non-compact morphology with some particularly fine equiaxed crystals which developed deficiently.

关键词： galvanizing third generation automotive steel oxide morphology galvanizability

Photoactivated Circularly Polarized Room-Temperature Phosphorescence from Phenoselenazine Derivative and Its Application in Information Security

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Chinese Journal of Chemistry 2024年第20期42卷 2499-2506页

作者： Shiyao fu Yi Chen Yujun Xie zhen Li Institute of Molecular Aggregation Science Tianjin UniversityTianjin 300072China Joint Schoolof National University of Singapore and Tianjin University International Campus of Tianjin UniversityBinhai New City FuzhouFujian 350207China Hubei Key Lab on Organic and Polymeric Opto-Electronic Materials Department of ChemistryWuhan UniversityWuhanHubei 430072China

Room-temperature phosphorescence(RTP)materials have experienced rapid development due to their potential in organic light-emitting diode,information security,bioimaging,***,the design of chiral organic phosphors with circularly polarized RTP(CPP)property remains a formidable ***,we introduce a chiral perturbation approach using a combination of chiral binaphthol and phenoselenazine derivative to achieve *** photoactivated CPP in polystyrene(PS)film demonstrates a luminescence dissymmetry factor(glum),emission efficiency,and RTP lifetime up to 9.32×10^(–3),27.0%,and 40.0 ms,*** remarkable sensitivity of PS film to oxygen and temperature enables the adjustable emission colors,ranging from green to offwhite and blue under varying *** doping systems,utilizing hosts of triphenylphosphine and 9-phenylcarbazole,demonstrate an extended CPP lifetime of 85.9 ms and exhibit a persistent mechanoluminescence property with low pressure response threshold as low as 0.15 *** information security provided by this CPP material was attained via the using of diverse emission colors and afterglow generated by distinct UV irradiation times and host ***,it can also be achieved by observing different emission patterns using R-and *** research has presented a reliable approach for producing CPP materials with high emission efficiency and glum.

关键词： Room-temperature phosphorescence Circularly polarized luminescence Spin-orbit coupling Host-guest systems Multi-stimuli-responsive luminescence Phenoselenazine

Influence of mechanical reduction amount on internal quality of continuous casting billets by thermal and numerical simulation

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Journal of Iron and Steel Research International 2023年第6期30卷 1234-1243页

作者： Dan-qing Jiang Shu-jian Sun Han Wu Yang-jian Xu fu-hai Zhu zhen-qiang Zhang Jiang Wang Zhong-ming Ren School of Materials Science and Engineering Shanghai UniversityShanghai 200444China State Key Laboratory of Advanced Special Steel Shanghai UniversityShanghai 200444China

With establishment of thermal and numerical simulation models,the influence of reduction amount on solidification structure,segregation and shrinkage porosity of continuous casting(CC)billets was *** thermal–mechanical coupled simulation results indicated that with an increase in reduction amount,the temperature in the central area decreases,and the reduction efficiency firstly increases and then decreases,reaching the maximum value at reduction amount of 6 *** analysis showed that increasing the reduction amount is beneficial for the refinement of central solidification ***,the internal cracks are more likely to appear at higher reduction *** X-ray computerized tomography results revealed that a higher reduction amount can significantly reduce the volume fraction and equivalent diameter of the central shrinkage porosities of CC billets and increase the sphericity of ***,the macrosegregation of carbon along the central line is improved as the reduction amount increases;while the reduction amount exceeds 8 mm,the segregation degree will not change any more.

关键词： Mechanical reduction Solidification structure Porosity Thermal simulation Continuous casting billet

Effects of initial grain size and strain on grain boundary engineering of high-nitrogen CrMn austenitic stainless steel

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International Journal of Minerals,Metallurgy and Materials 2018年第8期25卷 922-929页

作者： zhen-hua Wang Jian-jun Qi Wan-tang fu School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China HBIS Group Technology Research Institute Shijiazhuang 050023China

18 Mn18 Cr0.5 N steel with an initial grain size of 28–177 μm was processed by 2.5%–20% cold rolling and annealing at 1000°C for 24 h,and the grain boundary character distribution was examined via electron backscatter *** strain(2.5%) favored the formation of low-Σ *** this strain,the fraction of low-Σ boundaries was insensitive to the initial grain ***,specimens with fine initial grains showed decreasing grain size after grain boundary engineering *** fraction of low-Σ boundaries and the(Σ9 + Σ27)/Σ3 value decreased with increasing strain; furthermore,the specimens with fine initial grain size were sensitive to the ***,the effects of the initial grain size and strain on the grain boundary engineering were discussed in detail.

关键词： grain boundary engineering grain boundary character distribution grain size strain austenitic stainless steel