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Application of kernel methods in signals modulation classification

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The Journal of China Universities of Posts and Telecommunications 2011年第1期18卷 84-90页

作者： ZHOU Xin WU Ying WANG da-lei Institute of Engineering Information Engineering University Zhengzhou 450002 China

A new approach to common signals classification of relevance vector machine （RVM） was presented and two signal classifiers based on kernel methods of support vector machine （SVM） and RVM were compared and analyzed. First several robust features of signals were extracted as the input of classifiers, then the kernel thought was used to map feature vectors impliedly to the high dimensional feature space, and multi-class RVM and SVM classifiers were designed to complete AM, CW, SSB, MFSK and MPSK signals recognition. Simulation result showed that when chose proper parameter, RVM and SVM had comparable accuracy but RVM had less learning time and basis functions. The classification speed of RVM is much faster than SVM.

关键词： kernel function sparse Bayesian model RVM SVM

Prediction of Aircraft Engine Health Condition Parameters Based on Ensemble ELM

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Journal of Harbin Institute of Technology(New Series) 2013年第3期20卷 7-11页

作者： da lei Shi-Sheng Zhong School of Mechatronics Engineering Harbin Institute of Technology

In view of aircraft engine health condition parameters prediction,an ensemble ELM based prediction approach is proposed in this paper. In the approach,the AdaBoost. RT algorithm is improved to adjust its threshold adaptively,and is utilized as the basic framework to establish the ensemble learning model using ELM as weak learners. The proposed approach is evaluated through the prediction of the actual engine fuel flow deviation time series,and the results demonstrate that this approach is feasible for the prediction of aircraft engine health condition parameters. The performance of the proposed approach is compared with single ELM, single process neural network ( PNN) ,and a similar ensemble ELM based approach using AdaBoost. RT as basic framework. The results show that,the proposed approach is more accurate than single ELM and single PNN,and no worse than the ensemble prediction approach for contrast,furthermore,the given approach is more convenient for practical application. Therefore,the proposed approach is better suited to the prediction of aircraft engine health parameters.

关键词： ensemble learning AdaBoost. RT ELM aircraft engine condition parameter prediction

Recent progress in the fields of tuning the band gap of quantum dots

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Science China(Technological Sciences) 2012年第4期55卷 903-912页

作者： lei da SHEN YongTao FENG YiYu FENG Wei School of Materials Science and Engineering Tianjin UniversityTianjin 300072China

Band gap, which can be tuned by changing the size of quantum dots (QDs) based on the quantum confinement effect, plays a fundamental role in electrical and optical properties of QDs. However, the tuning of the band gap by changing the size results in a series of intrinsic problems, such as the instability of the extremely small QDs, negative combination with biomolecules because of the large size of QDs, etc. Recently, several new methods have been developed to further study and improve the tuning of the band gap. In this paper, we summarized the recent progress in the fields of tuning the band gap of QDs, including alloyed QDs, core-shell QDs and doped QDs. The review has also prospected the development trend of tuning the band gap as well as their applications.

关键词： quantum dots band gap photoluminescence alloying core-shell doping

Summary of technology for a comprehensive geophysical exploration of gold mine in North China Craton

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Science China Earth Sciences 2021年第9期64卷 1524-1536页

作者： Qingyun DI Guoqiang XUE da lei Qingdong ZENG Changmin FU Zhiguo AN CAS Engineering Laboratory for Deep Resources Equipment and Technology Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China Key Laboratory of Shale Gas and Geoengineering Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China Key Laboratory of Mineral Resources Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing100049China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing100029China

The North China Craton is the oldest continental block,and has suffered from large-scale lithospheric thinning and destruction,which in turn led to gold deposits in northern *** decratonic gold deposits in the North China Craton became the most important gold deposits in China,and geophysical methods are key means to detect and discover gold deposits *** this paper,based on the geological and petrophysical characteristics of the North China Craton,the geological model of the decratonic gold deposits is transformed into a geophysical *** present,two methods of geophysical exploration of decratonic gold deposits are in use:rapid and efficient exploration on the scale of the ore concentration area,and large depth exploration on the scale of the deposit *** detail,the airborne electromagnetic,magnetic and gravity methods are used to detect the shallow(1,500 m)anomaly area on the scale of the ore concentration *** the ground-controlled source electromagnetic and ground magnetotelluric methods,explorations for targets at significant depth(5,000 m)are carried out in the mining ***,taking the Liaodong ore concentration area as an example,geophysical methods are used to discover two prospecting areas around the Jianshanzi Fault in the Qingchengzi ore concentration area,Baiyun-Xiaotongjiapuzi deep prospecting area,and Qingchengzi deep prospecting ***,three prospecting areas are delineated around the Jixingou Fault in the Wulong mining area,Wulong deep prospecting area,Weishagou deep prospecting area,and Chang’an deep prospecting *** anomalies in the ore concentration area and mining area are revealed by means of three-dimensional exploration methods,thereby providing technical support for the exploration of metal minerals such as decratonic gold deposits.

关键词： Decratonic gold deposits in the North China Craton Liaodong area Integrated geophysics Mining area scale Deposit area scale

Ginsenosides stimulated the proliferation of mouse spermatogonia involving activation of protein kinase C

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2009年第2期10卷 87-92页

作者： da-lei ZHANG Kai-ming WANG Cai-qiao ZHANG Key Laboratory of Animal Epidemic Etiology and Immunological Prevention of the Ministry of Agriculture College of Animal Sciences Zhejiang University Hangzhou 310029 China College of Medicine Nanchang University Nanchang 330006 China

The effect of ginsenosides on proliferation of type A spermatogonia was investigated in 7-day-old mice. Spermatogonia were characterized by c-kit expression and cell proliferation was assessed by immunocytochemical demonstration of proliferating cell nuclear antigen (PCNA). After 72-h culture, Sertoli cells formed a confluent monolayer to which numerous spermatogonial colonies attached. Spermatogonia were positive for c-kit staining and showed high proliferating activity by PCNA expression. Ginsenosides (1.0～10 μg/ml) significantly stimulated proliferation of spermatogonia. Activation of protein kinase C (PKC) elicited proliferation of spermatogonia at 10-8 to 10-7 mol/L and the PKC inhibitor H7 inhibited this effect. Likewise, ginsenosides-stimulated spermatogonial proliferation was suppressed by combined treatment of H7. These results indicate that the proliferating effect of ginsenosides on mouse type A spermatogonia might be mediated by a mechanism involving the PKC signal transduction pathway.

关键词： Ginsenosides Spermatogonia Protein kinase C Mouse

Experimental study on seismic reinforcement of bridge foundation on silty clay landslide with inclined interlayer

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Earthquake Engineering and Engineering Vibration 2024年第1期23卷 193-207页

作者： lei da Xiao Hanmo Ran Jianhua Luo Bin Jiang Guanlu Xue Tianlang College of Civil Engineering Sichuan Agricultural UniversityDujiangyan 611830China Sichuan Higher Education Engineering Research Center for Disaster Prevention and Mitigation of Village Construction Dujiangyan 611830China School of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China

A shaking table test for a bridge foundation reinforced by anti-slide piles on a silty clay landslide model with an inclined interlayer was *** deformation characteristics of the bridge foundation piles and anti-slide piles were analyzed in different loading *** dynamic response law of a silty clay landslide with an inclined interlayer was *** spacing between the rear anti-slide piles and bridge foundation should be reasonably controlled according to the seismic fortification requirements,to avoid the two peaks in the forced deformation of the bridge foundation ***“blocking effect”of the bridge foundation piles reduced the deformation of the forward anti-slide *** stress-strain response of silty clay was intensified as the vibration wave field appeared on the *** the vibration intensified,the thrust distribution of the landslide underwent a process of shifting from triangle to inverted trapezoid,the difference in the acceleration response between the bearing platform and silty clay landslide tended to decrease,and the spectrum amplitude near the natural vibration frequency *** rear anti-slide piles were able to slow down the shear deformation of the soil in front of the piles and avoid excessive acceleration response of the bridge foundation piles.

关键词： silty clay landslide inclined interlayer shaking table test anti-slide pile bridge foundation pile

Effects of high temperature during grain filling on physicochemical properties of waxy maize starch

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Journal of Integrative Agriculture 2016年第2期15卷 309-316页

作者： LU da-lei YANG Huan SHEN Xin LU Wei-ping Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops Yangzhou University

Understanding the waxy maize starch physicochemical properties response to heat stress during grain filling could improve starch *** effects of heat stress during early（1-15 days after pollination,daP） and late（16-30 daP） grain filling stages on the starch physicochemical properties of four waxy maize varieties were *** only increased in Suyunuo 5 after exposure to high temperature at late grain filling *** effects of heat stress on digestibility and swelling power were dependent on varieties and ***,swelling power was increased by heat stress at early grain development stage and digestibility was increased by high temperature at late grain filling stage,*** results of correlation analysis indicated the starch with large granule size could swell well and easy ***,trough,final,and breakdown viscosities in response to heat stress were dependent on stages and *** general,peak,trough and final viscosities were decreased and increased by heat stress at early grain formation and late grain filling stages,respectively;whereas the breakdown and setback viscosities were similar among the three *** stress increased the gelatinization temperatures and retrogradation *** range decreased under heat stress at 1-15 daP but remained constant under heat stress at 16-30 daP in all *** starch exposed to high temperature at 16-30 daP presented higher digestibility and peak viscosity and lower retrogradation percentage than those at 1-15 ***,heat stress at early grain formation stage severely affects the physicochemical properties of starch.

关键词： waxy maize heat stress digestibility pasting gelatinization retrogradation

Regulation of pseudographitic carbon domain to boost sodium energy storage

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Nano Research 2024年第6期17卷 5188-5196页

作者： Zhidong Hou Mingwei Jiang da lei Xiang Zhang Yuyang Gao Jian-Gan Wang State Key Laboratory of Solidification Processing Center for Nano Energy MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical University and Shaanxi Joint Lab of Graphene(NPU)Xi’an 710072China

Hard carbon anode has shown extraordinary potentials for sodium-ion batteries(SIBs)owing to the cost-effectiveness and advantaged ***,the widespread application of hard carbon is still hindered by the insufficient sodium storage capacity and depressed rate property,which are mainly induced by the undesirable pseudographitic ***,we develop a molten-salt-mediated strategy to regulate the pseudographitic structure of hard carbon with suitable interlayer spacing and enlarged pseudographitic domain,which is conducive to the intercalation capacity and diffusion kinetics of sodium ***,the optimized hard carbon anode delivers a high reversible capacity of 320 mAh·g^(−1),along with superior rate property(138 mAh·g−1 at 2 A·g^(−1))and stable cyclability over 1800 ***,the in situ Raman spectroscopic study and full-cell assembly further investigate the sodium storage mechanism and practical implement of obtained hard *** work pioneers a low-cost and effective route to regulate the pseudographitic structure of hard carbon materials for advanced SIBs.

关键词： pseudographitic structure molten salt hard carbon anode sodium-ion batteries

Quaternized polymer binder for lithium-sulfur batteries:The effect of cation structure on battery performance

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Journal of Energy Chemistry 2020年第4期29卷 165-172页

作者： Fang Wang Lv Li da lei Yongpeng Li He Yang Weili Zhu Fengxiang Zhang State Key Laboratory of Fine Chemicals School of Chemical and Petroleum EngineeringDalian University of Technology2 Dagong RoadLiaodongwan NewDistrictPanjin 124221LiaoningChina

Lithium–sulfur (Li–S) batteries are great candidates for energy storage systems, but need to overcome theissues of low sulfur utilization and polysulfide shuttling for use in large-scale commercial ***, quaternized polymers have received much attention for their polysulfide trapping propertiesdue to electrostatic interaction. In this work, we report a series of polyarylether sulfone (PSF) binderswith different cation structures including imidazolium (Im), triethylammonium (Tr), and morpholinium(Mo). The ability of the these quaternized binders and the conventional poly(vinylidene fluoride) or PVDFbinder to capture polysulfide increases in the order of PVDF dazolium cation may promote the interaction between PSF-Im and polysulfide asindicated by an X-ray photoelectron spectroscopic study. The PSF-Im based cathodes showed the highestcapacity retention (77% at 0.2 C after 100 cycles and 84% at 0.5 C after 120 cycles), and the bestrate capability. This work demonstrates the importance of the cation structure in the design of efficientquaternized binders for high performance Li–S batteries.

关键词： Quaternized binder Polysulfide Cycle stability Li-S battery