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CSEE Journal of Power and Energy Systems 2024年第2期10卷 756-766页

作者： Yanxiong Lei Guiping du Tuhuan li Wenjie Ma Xueyi Wang School of Electric Power South China University of TechnologyGuangzhou 510641China

Integrated battery chargers are highly effective for saving costs and improving the power density of on-board chargers in electric vehicles (EVs), However, achieving torque elimination of the commonly used three-phase (3p) motors during the fast-charging process is challenging. In this paper, the general torque cancelation law applied in 3p permanent magnet synchronous motors (PMSMs) and induction motors (IMs) is derived to design high power density integrated fast battery chargers. Two novel integrated systems with fast-charging and vehicle-to-grid (V2G) capabilities are proposed based on this law. The main advantages of the proposed systems are: (1) Two filter inductors are constituted by the stator windings while charging, and only one external inductor and several contactors are supplemented to the motor-drive circuit. Therefore, the proposed integrated systems possess high power density;(2) The 3p open-winding (OW) motor is employed, with no need to modify the propulsion system or redesign the interior structure of the motor;(3) Employing an individual controller for each phase of the inner current loop control, the proposed systems realize unity power factors and low current harmonics in the fast-charging and V2G mode. Simulation and experimental results verify the feasibility of the proposed topologies and control strategies.

关键词： Electric vehicles(EVs) fast charging integrated battery charger 3p PMSM/IM torque cancelation

Fourth-order phase-field modeling for brittle fracture in piezoelectric materials

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Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 837-856页

作者： Yu tan Fan PENG Chang liU Daiming PENG Xiangyu li State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China College of Science Chang'an UniversityXi'an 710064China Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province School of Mechanics and Aerospace EngineeringSouthwest Jiaotong UniversityChengdu 610031China

Failure analyses of piezoelectric structures and devices are of engineering and scientific *** this paper,a fourth-order phase-field fracture model for piezoelectric solids is developed based on the Hamilton *** typical electric boundary conditions are involved in the present model to characterize the fracture behaviors in various physical situations.A staggered algorithm is used to simulate the crack *** polynomial splines over hierarchical T-meshes(PHT-splines)are adopted as the basis function,which owns the *** numerical simulations are performed to study the influence of the electric boundary conditions and the applied electric field on the fracture behaviors of piezoelectric *** electric boundary conditions may influence crack paths and fracture loads *** present research may be helpful for the reliability evaluation of the piezoelectric structure in the future applications.

关键词： isogeometric analysis(IGA) brittle fracture fourth-order phase-field model piezoelectric solid

Nest complexity correlates with larger brain size but smaller body mass across bird species

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Integrative Zoology 2024年第3期19卷 496-504页

作者： Shaobin li Yuxin liU Xiaolong du Guopan li Wenbo liAO College of life Science Yangtze UniversityJingzhouChina Key Laboratory of Southwest China Wildlife Resources Conservation(Ministry of Education) China West Normal UniversityNanchongChina

Amniotes differ substantially in absolute and relative brain size after controlling for allometry,and numerous hypotheses have been proposed to explain brain size *** size is thought to correlate with processing capacity and the brain’s ability to support complex manipulation such as nest-building *** increased complexity of nest structure is supposed to be a measure of an ability to manipulate nesting material into the required *** degree of nest-structure complexity is also supposed to be associated with body mass,partly because small species lose heat faster and delicate and insulated nests are more crucial for temperature control of eggs during incubation by small ***,we conducted comparative analyses to test these hypotheses by investigating whether the complexity of species-typical nest structure can be explained by brain size and body mass(a covariate also to control for allometric effects on brain size)across 1353 bird species from 147 *** with these hypotheses,our results revealed that avian brain size increases as the complexity of the nest structure increases after controlling for a significant effect of body size,and also that a negative relationship exists between nest complexity and body mass.

关键词： body size brain size comparative analysis nest building nest type reproductive investment

Energy mechanism of bolt supporting effect to fissured rock under static and dynamic loads in deep coal mines

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International Journal of Mining Science and Technology 2024年第3期34卷 371-384页

作者： Deyuan Fan Xuesheng liu Yunliang tan Xuebin li Shenglong Yang College of Energy and Mining Engineering Shandong University of Science and TechnologyQingdao 266590China State Key Laboratory of Mining Disaster Prevention and Control Shandong University of Science and TechnologyQingdao 266590China National Energy Group Ningxia Coal Industry Co. Ltd.Yinchuan 753001China

The stability control of fissured rock is difficult,especially under static and dynamic loads in deep coal *** this paper,the dynamic mechanical properties,strain rate evolution and energy dissipation of fissured and anchored rocks were respectively obtained by SHPB *** was found that bolt can provide supporting efficiency-improving effect for fissured rock against dynamic disturbance,and this effect increased quadratically with decrease in anchoring ***,the energy dissipation mechanism of anchored rock was obtained by slipping ***,bolt energy-absorbing mechanism by instantaneous tensile-shear deformation was expressed based on material mechanics,which was the larger the anchoring angle,the smaller the energy absorption,and the less the contribution to supporting efficiency *** this basis,the functional relationship between energy dissipation of anchored rock and energy absorption of bolt was *** the coal-gangue separation system of Longgu coal mine as an example,the optimal anchoring angle can be determined as 57.5°–67.5°.Field monitoring showed fissured rock with the optimal anchoring angle,can not only effectively control the deformation,but also fully exert the energy-absorbing and efficiency-improving effect of bolt *** study provides guidance to the stability control and supporting design for deep engineering under the same or similar conditions.

关键词： Static and dynamic loads Anchored rock Energy absorption Anchoring angle Engineering verification

Efficient nitrite-to-ammonia electroreduction over Zr-Ni frustrated Lewis acid-base pairs

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Science China Chemistry 2024年第5期67卷 1707-1714页

作者： Ying Zhang Zhuohang li Wenyu du Kai Chen Ke Chu School of Materials Science and Engineering Lanzhou Jiaotong UniversityLanzhou 730070China

Electrochemical NO_(2)~--to-NH_(3) conversion(NO_(2)RR) offers a green route to NH_(3) electrosynthesis, while developing efficient NO_(2)RR catalysis systems at high current densities remains a grand challenge. Herein, we report an efficient Zr-NiO catalyst with atomically dispersed Zr-dopants incorporated in NiO lattice, delivering the exceptional NO_(2)RR performance with industriallevel current density(>0.2 A cm^(-2)). In situ spectroscopic measurements and theoretical simulations reveal the construction of ZrNi frustrated Lewis acid-base pairs(FLPs) on Zr-Ni O, which can substantially increase the number of absorbed nitrite(NO_(2)~-),promote the activation and protonation of NO_(2)~- and concurrently hamper the H coverage, boosting the activity and selectivity of Zr-NiO towards the NO_(2)RR. Remarkably, Zr-NiO exhibits the exceptional performance in a flow cell with high Faradaic efficiency for NH_(3) of 94.0% and NH_(3)yield rate of 1,394.1 μmol h^(-1)cm^(-2) at an industrial-level current density of 228.2 m A cm^(-2),placing it among the best NO_(2)RR electrocatalysts for NH_(3) production.

关键词： electrochemical nitrite-to-ammonia conversion frustrated Lewis acid-base pairs(FLPs) in situ spectroscopy theoretical computations

Process intensification for the synthesis and purification of battery-grade li_(2)CO_(3)with microfluidics

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Particuology 2024年第7期90卷 106-117页

作者： Haodu li Jie Zhang lin Dai Le du Jiqin Zhu The State Key Laboratory of Chemical Resource Engineering College of Chemical EngineeringBeijing University of Chemical TechnologyBeijing 100029China

Battery-grade lithium carbonate(li_(2)CO_(3))with a purity of higher than 99.5 wt%is of great importance as a high value-added lithium ***,influences of different reaction systems and process control on product purity remain ***,a membrane dispersion microreactor was used to enhance the mass transfer of preparation and purification processes in homogeneous and heterogeneous *** systems of Na_(2)CO_(3)–liCl,NH_(4)HCO_(3)–liCl,and NH_(3)·H_(2)O−CO_(2)−liCl,CO_(2)purification based on carbonation and decomposition were *** li_(2)CO_(3)purity was increased by the improvement of mixing *** carbonation time was reduced by 62.5%and 58.3%for the NH_(3)·H_(2)O−CO_(2)and CO_(2)purification systems,*** the two ammonia-based systems,li_(2)CO_(3)particles with a purity of 99.7–99.8 wt%were one-step prepared with a size of 3–5μm,which also met the requirement of the battery-grade *** purity was further increased to 99.9 wt%by CO_(2)purification and liHCO_(3)*** investigation could provide a feasible alternative for the controllable preparation of battery-grade li_(2)CO_(3)in one or multiple steps.

关键词： Microfluidics Battery grade li_(2)CO_(3) Process intensification High purity

A stepwise approach to enhancing flotation of low-grade zinnwaldite through the cationic/DL-2-octanol/anionic reagent combinations: Behavior and mechanism analysis

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International Journal of Mining Science and Technology 2024年第6期34卷 881-891页

作者： Zhonghua Xue Yali Feng Haoran li Jinrong Ju Xingquan du School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China Key Laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

In order to alleviate the pressure on the supply of lithium resources, this research proposes the use of binary/ternary collectors with high selectivity and collecting ability to enhance the flotation purification of low-grade zinnwaldite ore. The binary collector is a mixture of dodecylamine polyoxyethylene ether and DL-2-octanol. A binary collector is added first, followed by sodium oleate, known as a ternary collector. Under acidic conditions, the recovery of li2O in the concentrate was increased by 8.26% with the binary collector and 13.70% with the ternary collector, compared to the dodecylamine polyoxyethylene ether. The binary collector enhanced the dispersibility of the single collector, while co-adsorption strengthened the hydrophobic nature of the zinnwaldite surface. Consequently, zinnwaldite particles,after the application of binary collector, displayed inter-particle flocculation and attachment to bubbles within 60×10^(-9)m compared to other particles. Ternary collector exhibited the capacity to lower critical micelle concentration and surface tension, subsequently inducing a denser and thicker hydrophobic layer through electrostatic forces, hydrophobic interactions, and chemical reactions. The objective of this research is to facilitate the recovery of lithium resources from low-grade ores in order to meet the needs of sustainable development.

关键词： Zinnwaldite Molecular dynamics simulation Flotation Ternary collector Extended DLVO theory

Distributed power conditioning unit of large-scale space solar power station

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Chinese Journal of Aeronautics 2024年第8期37卷 421-434页

作者： Xintong li Jianwei MI Yiqun ZHANG Guanheng FAN Jie du School of Mechano-electronic Engineering Xidian UniversityXi’an 710071China Shaanxi Key Laboratory of Space Solar Power Station System Xidian UniversityXi’an 710071China Academy of Advanced Interdisciplinary Research Xidian UniversityXi’an 710071China

In this paper,a multi-bus distributed Power Conditioning Unit(PCU)is proposed for the Space Solar Power Station with large scale photovoltaic(PV)array and power levels reaching MW *** this unit,there are multiple independent PV *** each PV array,there are multiple independent PV *** this paper,a V-P droop control method with adaptive droop coefficient is proposed,which modifies the droop intercept based on the bus voltage deviation and the power per unit value of the PV *** method ensures the accuracy of bus voltage and achieves proportional distribution of power between PV arrays based on the proposed topology structure in this *** the load changes or the output power of the PV array fluctuates,this method can ensure that power is distributed *** principle and control method of the proposed droop control method is analyzed in this *** effectiveness of the method is verified through MATLAB/Simulink simulation and *** and experimental results show that the proposed method can achieve power distributed proportionally when load changes and PV output power fluctuates,reduce bus voltage error caused by line impedance and differences in rated power of different PV arrays,and improve the performance of PV power generation system applied to space.

关键词： Space Solar Power Station Photovoltaics Droop control DC confluence Power conditioning unit

Preparation of three-dimensional nanoporous copper foil with high specific surface area

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Rare Metals 2024年第7期43卷 3430-3437页

作者： Ning Song li-Juan Wang Jun-Feng Wang Juan liao Jian Huang Peng-Kang du Yun-Zhi tang Yu-Hui tan Xiao-Wei Fan Jiangxi Provincial Key Laboratory of Functional Molecular Materials Chemistry School of Chemistry and Chemical EngineeringJiangxi University of Science and TechnologyGanzhou 341000China

The porous copper foil material has the advantages of ultralight and ultra-thin,and can prevent dangers such as thermal runaway and battery fire,which could be regarded as a prospective material for lithium battery **... 详细信息

关键词： copper porous dimensional

Constraints on crustal compositional architecture across the North China-Altaids transition and implications for craton margin reworking

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National Science Review 2024年第05期11卷 121-133页

作者： Zhuo Ye Xiaomiao tan Rui Gao Qiusheng li Hongshuang Zhang Xiaoyang Wu Wenhui li Yingkang li Sino Probe Center Chinese Academy of Geological Sciences Key Laboratory of Deep-Earth Dynamics Ministry of Natural Resources Institute of Geology Chinese Academy of Geological Sciences School of Earth Sciences and Engineering Sun Yat-sen University Key Laboratory of Marine Geology and Environment Institute of OceanologyChinese Academy of Sciences China Geological Sample Information Center China Geological Survey

The phase of secular evolution of continents is manifested as the degree of compositional differentiation,modification and maturation of continental crusts, which is vital in understanding the mechanism of continental evolution but is difficult to quantify. Here we use integrated passive-and active-source seismic profiling to conduct joint analysis and inversion and derive Vs and Vp/Vs section models across the North China Craton(NCC) to southeastern Altaids boundary zone that bears a tectonic transition from a reworked ancient craton margin to a Phanerozoic accretionary orogen. We systematically exploited the imaged multiple physical properties as precise and delicate proxies to constrain the compositional architecture in the crust across this important tectonic transition subject to various crustal evolutional phases. Our Vs and Vp/Vs imaging, together with the existing isotopic data, characterizes the Yin Shan–Yan Shan belt as the northern NCC margin with layered homogeneous compositions that point to an evolved crust. However, the lower-crustal low-Vs/high-Vp/Vs signature that overlaps the shallowly dipping to horizontal reflective fabrics suggests that the crust of the northern NCC margin has undergone considerable reworking through lower-crustal-stretching-assisted melt migration and mixing since the late Paleozoic to Mesozoic eras. The process probably involved crust–mantle interaction and thus resulted in a compositionally modified ancient crustal basement. On the contrary, the southeastern Altaids domain manifests crustal complexity in compositions and structures inferred to be indicative of a juvenile crust of the Phanerozoic accretionary orogen. Our results provide deep physical-property constraints that shed new light on the crustal evolution of a complex craton margin.

关键词： North China Craton Altaids crustal composition receiver function joint inversion continental reworking