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A tightly coupled rotational SINS/CNS integrated navigation method for aircraft

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Journal of Systems Engineering and Electronics 2019年第4期30卷 770-782页

作者： NING Xiaolin YUAN Weiping liu yanhong School of Instrument and Optoelectronic Engineering Beihang University

Strapdown inertial navigation system(SINS)/celestial navigation system(CNS)integrated navigation is widely used to achieve long-time and high-precision autonomous navigation for *** general,SINS/CNS integrated navigation can be divided into two integrated modes:loosely coupled integrated navigation and tightly coupled integrated *** the loosely coupled SINS/CNS integrated system is only available in the condition of at least three stars,the latter one is becoming a research *** major challenge of SINS/CNS integrated navigation is obtaining a high-precision horizon *** solve this problem,an innovative tightly coupled rotational SINS/CNS integrated navigation method is *** this method,the rotational SINS error equation in the navigation frame is used as the state model,and the starlight vector and star altitude are used as ***-physical simulations are conducted to test the performance of this integrated *** show that this tightly coupled rotational SINS/CNS method has the best navigation accuracy compared with SINS,rotational SINS,and traditional tightly coupled SINS/CNS integrated navigation method.

关键词： celestial navigation system(CNS) rotation modulation technology rotational strapdown inertial navigation system(SINS) rotational SINS/CNS integrated navigation

Preparation and characterization of Pt-WO_3/C catalysts for direct ethanol fuel cells

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Rare Metals 2010年第3期29卷 255-260页

作者： WU Feng liu yanhong WU Chuan School of Chemical Engineering and Environment Beijing Institute of Technology Beijing 100081 China National Development Center for High Technology Green Materials Beijing 100081 China

Three co-impregnation/chemical reduction methods in acidic solutions of pH 〈 1,including ethylene glycol （EG）,NaBH4,and HCOOH,were compared for Pt-WO3/C ***-WO3/C catalysts containing 10 wt.% and 20 wt.% platinum per carbon were prepared by the three methods; their morphology and electrocatalytic activities were *** 20 wt.% Pt-WO3/C catalyst prepared by the co-impregnation/EG method presented the optimal dispersion with an average particle size of 4.6 nm and subsequently the best electrocatalytic activity,and so,it was further *** anodic peak current density for ethanol oxidation from linear sweep voltammetry （LSV） is 7.9 mA·cm^-2,which is 1.4 and 5.2 times as high as those of the catalysts prepared by co-impregnation/NaBH4 and co-impregnation/ HCOOH reduction methods,2.1 times as high as that of the 10 wt.% Pt-WO3/C catalyst prepared by co-impregnation/EG method,respectively.

关键词： direct ethanol fuel cells catalysts preparation method characterization ethanol electrooxidation

Generalized mixed finite element method for 3D elasticity problems

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Acta Mechanica Sinica 2018年第2期34卷 371-380页

作者： Guanghui Qing Junhui Mao yanhong liu College of Aeronautical Engineering Civil Aviation University of China

Without applying any stable element techniques in the mixed methods, two simple generalized mixed element(GME) formulations were derived by combining the minimum potential energy principle and Hellinger–Reissner(H–R) variational principle. The main features of the GME formulations are that the common C0-continuous polynomial shape functions for displacement methods are used to express both displacement and stress variables, and the coefficient matrix of these formulations is not only automatically symmetric but also invertible. Hence, the numerical results of the generalized mixed methods based on the GME formulations are stable. Displacement as well as stress results can be obtained directly from the algebraic system for finite element analysis after introducing stress and displacement boundary conditions simultaneously. Numerical examples show that displacement and stress results retain the same accuracy. The results of the noncompatible generalized mixed method proposed herein are more accurate than those of the standard noncompatible displacement method. The noncompatible generalized mixed element is less sensitive to element geometric distortions.

关键词： Minimum potential energy principle Hellinger–Reissner (H–R) variational principle Generalized variational principle Generalized mixed element (GME) Elasticity problem Noncompatible mode

Preparation of Pt/C Nanocatalysts by Ethylene Glycol Method in Weakly Acidic Solutions

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Journal of Materials Science & Technology 2010年第8期26卷 705-710页

作者： Feng Wu yanhong liu Chuan Wu School of Chemical Engineering and Environment Beijing Institute of Technology Beijing 100081 China National Development Center for High Technology Green Materials Beijing 100081 China

Pt/C catalysts were prepared by ethylene glycol （EG） method in weakly acidic solutions adjusted by sodium citrate （NasCit）, sodium acetate （NaAc） and sodium hydroxide （NaOH）, separately. The effects of alkalizing agent, pH and temperature were investigated by transmission electron microscopy （TEM） and CV. The composition and structure of Pt/C catalyst prepared at optimal conditions of 140℃ and pH=6.7 adjusted by NasCit was further characterized by X-ray photoelectron microscopy （XPS） and X-ray diffraction （XRD）, respectively. The average particle size of Pt/C catalyst prepared using Na3Cit is 2.1 nm, smaller than that of Pt/C catalyst （2.9 nm） prepared using NaAc, much smaller than that of Pt/C catalyst （100 nm） prepared using NaOH. The electrocatalytic activity of Pt/C catalysts prepared using Na3Cit and NaAc for ethanol oxidation are 456.6 and 419.2 mA/mgPt, comparative to those of Pt/C catalyst prepared by typical EG method and commercial E-TEK Pt/C catalyst. Finally, the size control mechanism of Pt nanoparticles was discussed.

关键词： Platinum Nanocatalyst Formation mechanism Fuel Cell

Optimal search for moving targets with sensing capabilities using multiple UAVs

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Journal of Systems Engineering and Electronics 2017年第3期28卷 526-535页

作者： Xiaoxuan Hu yanhong liu Guoqiang Wang School of Management Hefei University of TechnologyHefei 230009China Key Laboratory of Process Optimization and Intelligent Decision-making Ministry of EducationHefei 230009China

This paper studies the problem of using multiple unmanned air vehicles (UAVs) to search for moving targets with sensing capabilities. When multiple UAVs (multi-UAV) search for a number of moving targets in the mission area, the targets can intermittently obtain the position information of the UAVs from sensing devices, and take appropriate actions to increase the distance between themselves and the UAVs. Aiming at this problem, an environment model is established using the search map, and the updating method of the search map is extended by considering the sensing capabilities of the moving targets. A multi-UAV search path planning optimization model based on the model predictive control (MPC) method is constructed, and a hybrid particle swarm optimization algorithm with a crossover operator is designed to solve the model. Simulation results show that the proposed method can effectively improve the cooperative search efficiency and can find more targets per unit time compared with the coverage search method and the random search method.

关键词： unmanned air vehicle (UAV) moving target search model predictive control path planning hybrid particle swarm optimization

Electro-deposition tangsten coating on low activation steel substrates from Na_2WO_4-ZnO-WO_3 melt salt

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Rare Metals 2012年第4期31卷 350-354页

作者： liu, yanhong Zhang, Yingchun liu, Qizong Ge, Changchun School of Material Science and Engineering University of Science and Technology BeijingBeijing 100083China

Tungsten coating is considered as a promising alternative material for plasma facing materials(PFC) in future fusion *** electro-deposition of tungsten in Na_2WO_4-ZnO-WO_3 melt at 1173 K on low activation steel substrates was studied in this *** and smooth tungsten films were deposited under various pulsed current *** crystal structure and microstructure of tungsten deposits were characterized by XRD,SEM and EDX *** results show that pulsed current density and duty cycle have a significant influence on tungsten nucleation and electro-crystallization *** and smooth tungsten coating with high purity and high adherence is obtained on low active steel substrates as cathodic current density ranges from 35 to 25 mA·cm_(-2).

关键词： tungsten electro-deposition low activation steel pulse current melt

Neutral and accumulator species in determining the spatial structure of tree species at different spatial scales

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Journal of Forestry Research 2019年第6期30卷 2175-2183页

作者： Jie Gao Chengyu Lü yanhong liu Forestry College of Beijing Forestry University

In 2014,a 40-ha undisturbed plot was established in the Beijing Songshan Nature *** spatial distribution and spatial associations of five dominant tree species of different height classes were examined using spatial point pattern analysis and the effects of these species on local community diversity assemblages were examined using the ISAR *** dominant species were characterized by an aggregated distribution at spatial scales of 0–50 *** smaller spatial scales,trees in larger height classes had significant positive and negative effects on the diversity of the lower height ***,at larger spatial scales this effect was *** small scales(0–10 m),accumulator species had positive effects on species diversity,maintained an over-representative proportion of diversity in their proximity,and supported the ecological niche *** the larger scale(10–50 m),neutral species were dominant and had positive effects on species diversity,though repeller species,which had negative effects on species diversity,also contributed to *** and accumulator species together determined local species diversity,but the relative importance of the two was closely related to spatial scale.A combination of the ecological niche theory and neutral processes together determines species coexistence and biodiversity of an undisturbed pine forest.

关键词： The 40-ha natural Chinese pine forest Spatial scale ISAR model Species coexistence Neutral and accumulator species

Key role of aπ–πcomplex in diaryl cross-coupling between aryldiazonium salts and arylboronic acids using photosensitizer-free gold/photoredox catalysis

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Organic Chemistry Frontiers 2022年第1期9卷 147-155页

作者： yanhong liu Rongxiu Zhu Chengbu liu Dongju Zhang Key Laboratory of Colloid and Interface Chemistry Ministry of EducationInstitute of Theoretical ChemistrySchool of Chemistry and Chemical EngineeringShandong UniversityJinan 250100P.R.China

DFT and TD-DFT calculations were performed to better understand the photosensitizer-free visible-lightmediated Au-catalyzed cross-coupling between aryldiazonium salts and arylboronic ***π–πtype complex between the aryldiazonium salt and the arylboronic acid,rather than either the generally accepted gold(I)–aryldiazonium salt complex or the aryldiazonium salt itself,was shown to play the role of a virtual *** oxidation of Au(I)to Au(III),the key aspect of the dual gold/photoredox catalytic aryl–aryl cross-coupling,occurs via the radical addition of an aryl radical rather than an aryldiazo radical on Au(II)*** transmetalation of the arylboronic acid to Au(III)species was identified as the rate-determining step,and the presence of a tetrafluoroborate anion can assist this process *** experimentally observed effect of substituents on the aryldiazonium salt and boronic acid on the reactivity was also rationalized.

关键词： boron coupling salts

China's Implementation of Goal 9 of the 2030 Agenda for Sustainable Development: International Capacity Cooperation under the Belt and Road Initiative

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Chinese Journal of Urban and Environmental Studies 2019年第1期7卷 65-85页

作者： liu yanhong Center for Public Policy Research University of Chinese Academy of Social Sciences

The experience in reform and opening up shows that China’s achievements in industrialization are largely attributed to its industrial openness towards the outside world and the international cooperation. As it enters the second decade of the 21st century, China’s industry has stepped into a new era of leading international development cooperation and promoting inclusive and sustainable growth in global industry, namely a period of developing international capacity cooperation supported by the Belt and Road Initiative(BRI). As vigorously driven by the BRI,the international capacity cooperation has not only pushed forward the creation of new industrial cooperation models among developing countries, but also opened new paths and contributed Chinese approaches to regional and global industrial cooperations under the new situation, in particular for the implementation of the inclusive and sustainable industrial development goal set in the United Nations 2030 Agenda for Sustainable Development. This mainly manifests as: dovetailing the top-level design with planning to build new mechanismbased capacity cooperation models, achieving cross-border infrastructure connectivity to promote trade, investment and industrial cooperation, constructing cooperation zones as an important platform for small and medium-sized enterprises to participate in capacity cooperation, breaking the financial bottleneck of regional development through diversified and open financial cooperation, and leading the leapfrog development of countries along the Belt and Road through technological cooperation and collaborative innovation.

关键词： 2030 Agenda for Sustainable Development the Belt and Road Initiative international capacity cooperation inclusive and sustainable industrialization new industrial cooperation models