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Design Method of Reversely Switched Dynistor Based Pulse Circuit Without Magnetic Switch

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CSEE Journal of Power and Energy Systems 2023年第1期9卷 306-314页

作者： Yicheng Pi lin liang Xiaoxue Yan State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074China

In the reversely switched dynistor(RSD)-based pulse power circuits,a magnetic switch is usually necessary to be applied together with a main *** occupies space and needs a magnetic *** this paper,a method of designing a RSD-based pulse circuit without a magnetic switch is *** the pulse circuit,a RBDT(reverse blocking diode thyristor)is used to separate the two capacitors and provide an energy *** pre-charge time of the RSD can be guaranteed by the energy conversion between the capacitors and inductors,instead of the saturation of the magnetic *** addition,the energy which is reused to trigger the RSD is based on an *** pulse circuit is evaluated by simulations and practical *** to the experimental results,the factors affecting the load pulse current and triggering of the RSD and RBDT are ***,a method to reduce the current in the trigger switch,which is a potential problem in the pulse circuit,is proposed.

关键词： Magnetic switch pulse power circuit reversely switched dynistor(RSD) reverse blocking diode thyristor(RBDT)

A Self-growing Porous Calcium-based Adsorbent Derived from Biowaste for Efficient Wastewater Purification

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Chinese Journal of Structural Chemistry 2021年第10期40卷 1328-1336页

作者： lin liang ZHUANG Zan-Yong Fujian Chuanzheng Communications College Fuzhou 350007China College of Materials Science and Engineering Fuzhou UniversityFuzhou 350108China Key Laboratory of Advanced Materials Technologies(Fuzhou University) Fujian Province UniversityFuzhou 350108China

Traditional adsorbents are normally suffered from a low adsorption capacity that has a finite saturated adsorption capacity. We reported herein a hierarchical self-growing porous calcium silicate hydrate(CSH) that uses biowaste as the precursor and is highly efficient in wastewater purification. In the process of phosphorus removal, CSH can react with phosphorus in water and grow into the hydroxyapatite(HAP). The generation of HAP further increases the active sites while maintains the porous structure of pristine CSH. Subsequently, the HAP could conduct the efficient extraction of Pb^(2+) from wastewater based on the ion exchange between Ca^(2+) and Pb^(2+). Clearly, the CSH structure has self-growing structure using the pollutants as the building blocks, not only achieving high adsorption capacity for pollutants, but also maintaining the hierarchically porous structure that supports the high efficiency in the next cycling. We provide here an intriguing pathway to tackle bottleneck of the traditional adsorbents, i.e., a finite saturated adsorption capacity.

关键词： self-growing model high adsorption capacity biowaste porous materials wastewater purifications

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Hydrogenation of phenylpyruvic acid to phenylalanine catalyzed by Ni-B/SiO_2

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Journal of Natural Gas Chemistry 2008年第3期17卷 303-308页

作者： Qunfang liang Aiqing Zhang lin Li Key Laboratory of Catalvsis and Materials Science of the State Ethnic Affairs Commission ＆ Ministry of Education College of Chemistry and MateriaLs Science South-Central University for Nationalities Wuhan 430074 Hubei China

Phenylalanine （Phe） is a significant amino acid that cannot be synthesized by human themselves but must be taken from environment. It was initially found that the nanosized amorphous Ni-B/SiO2 alloy prepared by the chemical reduction method was an effective catalyst for the preparation of Phe from phenylpyruvic acid （PPA） by amination and hydrogenation. It has been found that the amorphous Ni-B/SiO2 alloy catalyst exhibits superior activity and selectivity to the traditional catalysts Raney Ni and Urushibara nickel. The effects of reaction time, amounts of catalysts and ammonia solution, reaction temperature, and H2 pressure on the reaction have been investigated systematically. The results indicated that the yield of Phe was 97.9%, and the selectivity for Phe reached 98.9% when the reaction was carried out for 3 h at 333 K and 2.0 MPa of H2 with m（Cat.）： m（PPA） = 0.6 ： 1.0 and n（NH3）： n（PPA） = 3 ： 1. The catalysts were characterized by XRD, AAS, XPS, BET, and TEM, and the relationship between the catalyst structure and the catalytic activity was discussed in detail. It was found that the reason why Ni-B/SiO2 amorphous alloy catalyst was much more active for the preparation of Phe could be accounted for by the presence of electron-rich Ni due to electron donation from alloying B; the smaller size of Ni-B particles, the larger specific surface area of Ni-B/SiO2.

关键词： Ni-B/SiO2 amorphous alloy phenylalanine phenylpyruvic acid hydrogenation catalyst

Determining the road traffic accident hotspots using GIS-based temporal-spatial statistical analytic techniques in Hanoi,Vietnam

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Geo-Spatial Information Science 2020年第2期23卷 153-164页

作者： Khanh Giang Le Pei Liu liang-Tay lin College of Construction and Development Feng Chia UniversityTaichungTaiwanChina Faculty of Civil Engineering University of Transport and CommunicationsHanoiVietnam

This study applied GIS-based statistical analytic techniques to investigate the influence of accident Severity Index(SI)on temporal-spatial patterns of accident hotspots related to the specific time intervals of day and *** Traffic Accident(RTA)data in 3 years(2015-2017)in Hanoi,Vietnam were used to analyze and test this ***,the RTA data were divided into four seasons in accordance with Hanoi's weather conditions and the time intervals such as the daytime,nighttime,or peak ***,the Kernel Density Estimation(KDE)method was applied to analyze hotspots according to the time intervals and ***,the results were presented by using the comap *** study considered both analyses with and without *** accident SI measures the seriousness of an *** approach method is to give higher weights to the more serious accidents,but not with the extremely high values calculated on a direct rate to the accident *** results showed that both analyses determined the relatively similar hotspots,but the rankings of some hotspots were quite different due to the integration of *** is better to take into account SI in determining RTA hotspots because the gained results are more precise and the rankings of hotspots are more *** there,the traffic authorities can easily understand the causes behind each accident and provide reasonable solutions to solve the most dangerous hotspots in case of limited budget and resources *** is also the first study about this issue in Vietnam,so the contribution of the article will help the traffic authorities easily solve this problem not only in Hanoi but also in other cities.

关键词： Road Traffic Accident(RTA) hotspot GIS temporal-spatial analysis Kernel Density Estimation(KDE) Severity Index(SI)

Influence of Bipartite Qubit Coupling on Geometric Phase

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Communications in Theoretical Physics 2006年第1X期46卷 51-54页

作者： XING Lei liang Mai-lin Department of Physics Tsinghua University Beijing 100084 China Department of Physics Tianjin University Tianjin 300072 China

The geometric phase of the bipartite Heisenberg spin-1/2 system with one spin driven by rotating magnetic field is investigated. It is found that in the one-site drive case, the intersubsystem coupling can be equivalent to a static quasi-magnetic field in the parameter space. This perspective has satisfactorily explained the irregular asymptote effect of geometric phase. We discuss the property of the two-site magnetic drive spin system and discover that a stationary state with no geometric phase shift is generated.

关键词： geometric phase Heisenberg bipartite system rotating magnetic field

The Cauchy Boundary Value Problems on Closed Piecewise Smooth Manifolds in C^n

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Acta Mathematica Sinica,English Series 2004年第6期20卷 989-998页

作者： liang Yu lin Chun Hui QIU School of Mathematical Sciences Xiamen University Academy of Mathematics and System Science CAS

Suppose that D is a bounded domain with a piecewise C 1 smooth boundary in C n . Let ? ∈ C 1+α (?D). By using the Hadamard principal value of the higher order singular integral and solid angle coefficient method of points on the boundary, we give the Plemelj formula of the higher order singular integral with the Bochner–Martinelli kernel, which has integral density ?. Moreover, by means of the Plemelj formula and methods of complex partial differential equations, we discuss the corresponding Cauchy boundary value problem with the Bochner–Martinelli kernel on a closed piecewise smooth manifold and obtain its unique branch complex harmonic solution.

关键词： Bochner–Martinelli kernel Hadamard principal value Plemelj formula Boundary value problem

Dual-Functional Lithiophilic/Sulfiphilic Binary-Metal Selenide Quantum Dots Toward High-Performance Li-S Full Batteries

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Nano-Micro Letters 2023年第5期15卷 169-186页

作者： Youzhang Huang liang lin Yinggan Zhang Lie Liu Baisheng Sa Jie lin Laisen Wang Dong-liang Peng Qingshui Xie State Key Lab for Physical Chemistry of Solid Surfaces Fujian Key Laboratory of Surface and Interface Engineering for High Performance MaterialsCollege of MaterialsXiamen UniversityXiamen 361005People’s Republic of China Shenzhen Research Institute of Xiamen University Shenzhen 518000People’s Republic of China College of Materials Science and Engineering Multiscale Computational Materials FacilityFuzhou UniversityFuzhou 350100People’s Republic of China

The commercial viability of lithium-sulfur batteries is still challenged by the notorious lithium polysulfides(Li PSs)shuttle effect on the sulfur cathode and uncontrollable Li dendrites growth on the Li ***,a bi-service host with Co-Fe binary-metal selenide quantum dots embedded in three-dimensional inverse opal structured nitrogen-doped carbon skeleton(3DIO FCSe-QDs@NC)is elaborately designed for both sulfur cathode and Li metal *** highly dispersed FCSe-QDs with superb adsorptive-catalytic properties can effectively immobilize the soluble Li PSs and improve diffusion-conversion kinetics to mitigate the polysulfide-shutting ***,the 3D-ordered porous networks integrated with abundant lithophilic sites can accomplish uniform Li deposition and homogeneous Li-ion flux for suppressing the growth of *** advantage of these merits,the assembled Li-S full batteries with 3DIO FCSe-QDs@NC host exhibit excellent rate performance and stable cycling ability(a low decay rate of 0.014%over 2,000 cycles at 2C).Remarkably,a promising areal capacity of 8.41 mAh cm^(-2)can be achieved at the sulfur loading up to 8.50 mg cm^(-2)with an ultra-low electrolyte/sulfur ratio of 4.1μL mg^(-1).This work paves the bi-serve host design from systematic experimental and theoretical analysis,which provides a viable avenue to solve the challenges of both sulfur and Li electrodes for practical Li-S full batteries.

关键词： Dual-functional host Fe_(2)CoSe_(4)quantum dots Shuttle effect Dendrite-free Li anode Li-S full batteries

An improved boundary element method for modelling a self-reacting point absorber wave energy converter

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Acta Mechanica Sinica 2018年第6期34卷 1015-1034页

作者： Qian-Long Xu Ye Li Zhi-liang lin State Key Laboratory of Ocean Engineering Collaborative Innovation Center for Advanced Ship and Deep-Sea ExplorationMuti-function Towing TankKey Laboratory of Hydrodynamics(Ministry of Education)School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China

A numerical model based on a boundary element method (BEM) is developed to predict the performance of two-body selfreacting floating-point absorber (SRFPA) wave energy systems that operate predominantly in *** key numerical issues in applying the BEM are systematically *** particular,some improvements and simplifications in the numerical scheme are developed to evaluate the free surface Green's function,which is a main element of difficulty in the *** a locked SRFPA system,the present method is compared with the existing experiment and the Reynolds-averaged NavierStokes (RANS)-based method,where it is shown that the inviscid assumption leads to substantial over-prediction of the heave *** the unlocked SRFPA model we study in this paper,the additional viscous damping primarily induced by flow separation and vortex shedding,is modelled as a quadratic drag force,which is proportional to the square of body *** inclusion of viscous drag in present method significantly improves the prediction of the heave responses and the power absorption performance of the SRFPA system,obtaining results excellent agreement with experimental data and the RANS simulation results over a broad range of incident wave periods,except near resonance in larger wave height *** is found that the wave overtopping and the re-entering impact of out-of-water floating body are observed more frequently in larger waves,where these non-linear effects are the dominant damping sources and could significantly reduce the power output and the motion responses of the SRFPA system.

关键词： Boundary element method Floating-point absorber Heave Green's function Viscous drag

Feature Extraction of Kernel Regress Reconstruction for Fault Diagnosis Based on Self-organizing Manifold Learning

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Chinese Journal of Mechanical Engineering 2013年第5期26卷 1041-1049页

作者： CHEN Xiaoguang liang lin XU Guanghua LIU Dan School of Mechanical Engineering Xi’an Jiaotong University State Key Laboratory for Manufacturing Systems Engineering Xi’an Jiaotong University

The feature space extracted from vibration signals with various faults is often nonlinear and of high ***,nonlinear dimensionality reduction methods are available for extracting low-dimensional embeddings,such as manifold ***,these methods are all based on manual intervention,which have some shortages in stability,and suppressing the disturbance *** extract features automatically,a manifold learning method with self-organization mapping is introduced for the first *** the non-uniform sample distribution reconstructed by the phase space,the expectation maximization(EM) iteration algorithm is used to divide the local neighborhoods adaptively without manual *** that,the local tangent space alignment(LTSA) algorithm is adopted to compress the high-dimensional phase space into a more truthful low-dimensional ***,the signal is reconstructed by the kernel *** typical states include the Lorenz system,engine fault with piston pin defect,and bearing fault with outer-race defect are *** with the LTSA and continuous wavelet transform,the results show that the background noise can be fully restrained and the entire periodic repetition of impact components is well separated and identified.A new way to automatically and precisely extract the impulsive components from mechanical signals is proposed.

关键词： feature extraction manifold learning self-organize mapping kernel regression local tangent space alignment