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A strategic flight conflict avoidance approach based on a memetic algorithm

Chinese Journal of Aeronautics 2014年第1期27卷 93-101页

作者： Guan Xiangmin Zhang Xuejun han Dong Zhu Yanbo Lv Ji Su Jing School of Electronic and Information Engineering Beihang University National Key Laboratory of CNS/ATM Beihang University Aviation Data Communication Corporation

Conflict avoidance （CA） plays a crucial role in guaranteeing the airspace safety. The cur- rent approaches, mostly focusing on a short-term situation which eliminates conflicts via local adjust- ment, cannot provide a global solution. Recently, long-term conflict avoidance approaches, which are proposed to provide solutions via strategically planning traffic flow from a global view, have attracted more attentions. With consideration of the situation in China, there are thousands of flights per day and the air route network is large and complex, which makes the long-term problem to be a large-scale combinatorial optimization problem with complex constraints. To minimize the risk of premature convergence being faced by current approaches and obtain higher quality solutions, in this work, we present an effective strategic framework based on a memetic algorithm （MA）, which can markedly improve search capability via a combination of population-based global search and local improve- ments made by individuals. In addition, a specially designed local search operator and an adaptive local search frequency strategy are proposed to improve the solution quality. Furthermore, a fast genetic algorithm （GA） is presented as the global optimization method. Empirical studies using real traffic data of the Chinese air route network and daily flight plans show that our approach outper- formed the existing approaches including the GA .based approach and the cooperative coevolution based approach as well as some well-known memetic algorithm based approaches.

关键词： Air traffic control Combinatorial optimization Conflict avoidance Genetic algorithm Memetic algorithm

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One-step exfoliation and deprotonation of ANF/BNNS suspension for constructing 3D vertically aligned skeleton in epoxy-based thermal management composites

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Science China(Technological Sciences) 2022年第11期65卷 2675-2686页

作者： han GaoJie XUE PeiWen CAI ZhengHao FENG YueZhan LIU ChunTai SHEN ChangYu Key Laboratory of Materials Processing and Mold Ministry of Education National Engineering Research Center for Advanced Polymer Processing TechnologyZhengzhou UniversityZhengzhou450002China

Two-dimensional(2D)boron nitride nanosheet(BNNS)is promising in polymer-based thermal management materials(TMMs)by pre-constructing three-dimensional(3D)thermally conductive skeleton,but it yet suffers from the challenges of higheffective exfoliation and affinitive compatibility with *** this work,we developed a one-step exfoliation and deprotonation approach by the high-effective ball milling technique to prepare aramid nanofiber(ANF)/BNNS *** the strong collision/shear effect of ball-milling,micron-level h BN sheets were exfoliated into smaller and thinner BNNS with edge functional groups,meanwhile,poly-p-phenylene terephthalamide(PPTA)fibers were split into ANF by dissociating the intermolecular hydrogen *** importantly,both the exfoliation and deprotonation could be accelerated by each other to achieve a 100%yield of ANF/BNNS suspension with strong hydrogen/covalent bonding interactions between ***,the prepared ANF/BNNS suspension was used to construct 3D vertically aligned ANF/BNNS skeleton by the unidirectional freezing *** obtained epoxy-based composite(EP/ANF/BNNS)revealed excellent thermal conductivity of 2.41 W m^(-1)K^(-1) at 14.9 vol%BNNS loading due to the vertically oriented heat conduction paths and low interfacial thermal resistance in the ***,EP/ANF/BNNS composite showed high thermal stability and extraordinary fire retardancy with dramatically decreased heat release rate(265 W g^(-1)) and total heat release(20.6 kJ g^(-1)).Therefore,this work demonstrates a high-efficient one-step ball-milling exfoliation and deprotonation technique for preparing ANF/BNNS suspension,which reveals an enormous potential in preparing advanced TMMs by constructing 3D thermally conductive skeletons.

关键词： boron nitride nanosheet aramid nanofiber ball milling exfoliation thermal management composites

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Lifetime maximization via joint channel and power assignment for incremental-relay multi-channel systems

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Science China(Information Sciences) 2019年第2期62卷 119-130页

作者： Lihua PANG Yang ZhanG Ruiyu han Kaiyang BAI Guangliang REN JiANDong LI School of Information Engineering Xi'an University of Science and Technology State Key Laboratory of Integrated Service Networks Xidian University National Mobile Communications Research Laboratory Southeast University

A comprehensive resource optimization framework is designed for incremental amplify-andforward orthogonal frequency division multiplexing(AF-OFDM) relaying systems to maximize the network lifetime. Specifically, joint channel and power assignment, i.e., all degrees of freedom such as incremental policy, channel pairing, relay selection, and power allocation, are optimized with quality of service(QoS)constraints. The lifetime maximization problem is formulated as a mixed-integer nonlinear programming which at first glance seems mathematically intractable. However, a two-nested search loop, in which the outer loop varies the lifetime based on bisection criterion until finding the optimum while the inner loop attempts to derive the corresponding feasible solution set for that given lifetime by employing dual decomposition and subgradient techniques, is then presented to solve it. Numerical results are shown to verify the near-optimality and the effectiveness of our proposal.

关键词： lifetime maximization incremental relaying amplify-and-forward multi-channel systems resource optimization

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Carbonaceous and nitrogenous disinfection byproduct precursor variation during the reversed anaerobic–anoxic–oxic process of a sewage treatment plant

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Journal of Environmental Sciences 2018年第3期30卷 335-346页

作者： Huihui han Hengfeng Miao Yajing Zhang Minfeng Lu Zhenxing Huang Wenquan Ruan School of Environmental & Civil Engineering Jiangnan University Wuxi 214122 China Jiangsu Key Laboratory of Anaerobic Biotechnology Jiangnan University Wuxi 214122 China Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment Suzhou 215009 China

Disinfection byproduct（DBP）precursors in wastewater during the reversed anaerobic–anoxic–oxic（A^2/O）process,as well as their molecular weight（MW）and polarity-based fractions,were characterized with UV scanning,fluorescence excitation emission matrix,Fourier transform infrared and nuclear magnetic resonance *** DBP formation potentials（DBPFPs）after chlorination were further *** indicated that the reversed A^2/O process could not only effectively remove the dissolved organic carbon（DOC）and dissolved total nitrogen in the wastewater,but also affect the MW distribution and hydrophilic–hydrophobic properties of dissolved organic matter（DOM）.The accumulation of low MW and hydrophobic（HPO）DOM was possibly due to the formation of soluble microbial product-like（SMP-like）matters in the reversed A^2/O treatment,especially in the anoxic and aerobic ***,DOM in the wastewater displayed a high carbonaceous disinfection byproduct formation potential（C-DBPFP）in the fractions of MW100 k Da and MW5 k Da,and revealed an increasing tendency of nitrogenous disinfection byproduct formation potential（N-DBPFP）with decrease of *** polarity-based fractions,the HPO fraction of wastewater showed significantly higher C-DBPFP and N-DBPFP than hydrophilic and transphilic ***,although the reversed A^2/O process could remove most DBP precursors by DOC reduction,it led to the enhancement of DBPFP with the formation and accumulation of low MW and HPO *** addition,strong correlations between C-DBPFPs and SUVA,and between N-DBPFPs and DON/DOC,were observed in the wastewater,which might be helpful for DBPFP prediction in wastewater and reclaimed water chlorination.

关键词： Dissolved organic matter Reversed anaerobic-anoxic-oxicprocess Disinfection byproducts Chlorination Molecular weight Hydrophobic

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Influence of Zn and Mg Alloying on the Corrosion Resistance Properties of Al Coating Applied by Arc Thermal Spray Process in Simulated Weather Solution

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Acta Metallurgica Sinica(English Letters) 2018年第6期31卷 591-603页

作者： han-Seung Lee Seung-Jun Kwon Jitendra Kumar Singh Mohamed A.Ismail Department of Architectural Engineering Hanyang University Department of Civil Engineering Hannam University Department of Civil and Construction Engineering Faculty of Engineering and ScienceCurtin University Malaysia

In this study,Al–Zn and Al–Mg coatings were deposited on steel substrates by an arc thermal spray process.X-ray diffraction and scanning electron microscopy were used to characterize the deposited coatings and corrosion *** circuit potential（OCP）,electrochemical impedance spectroscopy,and potentiodynamic studies were used to assess the corrosion characteristics of these coatings after exposure according to the Society of Automotive Engineers（SAE）J2334 solution of varying *** solution simulates an industrial environment and contains chloride and carbonate ions that induce corrosion of the deposited ***,the Al–Mg alloy coating maintained an OCP of approximately-0.911 V versus Ag/Ag Cl in the SAE J2334 solution even after 792 h of *** indicates that it protects the steel sacrificially,whereas the Al–Zn coating provides only barrier-type protection through the deposition of corrosion *** Al–Mg coating acts as a self-healing coating and provides protection by forming Mg_6Al_2（OH）_（16）CO_3（Al–Mg layered double hydroxides）.Mg_6Al_2（OH）_（16）CO_3has interlocking characteristics with a morphology of plate-like nanostructures and an ion-exchange ability that can improve the corrosion resistance properties of the *** presence of Zn in the corrosion products of the Al–Zn coating allows dissolution,but,at the same time,Zn_5（OH）_6（CO_3）_2and Zn_6Al_2（OH）_（16）CO_3are formed and act to reduce the corrosion rate.

关键词： Self-healing coating Corrosion Arc thermal spray Electrochemical impedance spectroscopy

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Anti-adhesive Property of Maize Leaf Surface Related with Temperature and Humidity

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Journal of Bionic Engineering 2017年第3期14卷 540-548页

作者： Zhiwu han Jia Fu Yuqiang Fang Junqiu Zhang Shichao Niu Luquan Ren Key Laboratory of Bionic Engineering (Ministry of Education China) Jilin University Changchun 130022 China School of Mechanical Science and Engineering Jilin University Changchun 130022 China

The anti-adhesive surfaces have always aroused great interest of worldwide scientists and engineers. But in practical ap- plications, it often faces the threat and impact of temperature and humidity. In this work, the excellent anti-adhesive perform- ance of maize leaf under high temperature and humidity were investigated in detail. Firstly, the adhesion forces of the maize leaf surface under different temperature and humidity were measured by using Atomic Force Microscopy （AFM）. The temperature of the substrate was varied between 23 ~C to 100 ~C, and the ambient relative humidity is from 18% to 100%. It was found that the adhesion force of maize leaf decreased with the increase of temperature and humidity. The mechanism of its excellent anti-adhesive performance of maize leaf under high temperature and relative humidity was revealed. The transverse and lon- gitudinal ridges on maize leaf surface interlace with each other, forming small air pockets, which reduces the actual contact area between the object and the maize leaf. With the increase of humidity, the liquid film will be formed in the air pockets gradually and so much water vapor is produced with increase of tempera^tre. Then the air flow rate increases though the wavy top of transverse ridges, inducing the dramatic decrease of adhesion force. Inspired by this mechanism, four samples with this bionic structure were made. This functional ＂biomimetic structure＂ would have potential value in the wide medical equipments such as high frequency electric knife with anti-adhesion surface under high temperature and high humidity.

关键词： maize leaf anti-adhesion temperature relative humidity bionic surface

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Effect of alkalinity on nitrite accumulation in treatment of coal chemical industry wastewater using moving bed biofilm reactor

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Journal of Environmental Sciences 2014年第5期26卷 1014-1022页

作者： Baolin Hou Hongjun han Shengyong Jia Haifeng Zhuang Qian Zhao Peng Xu State Key Laboratory of Urban Water Resource and Environment Harbin Institute of Technology

Nitrogen removal via nitrite （the nitrite pathway） is more suitable for carbon-limited industrial wastewater. Partial nitrification to nitrite is the primary step to achieve nitrogen removal via nitrite. The effect of alkalinity on nitrite accumulation in a continuous process was investigated by progressively increasing the alkalinity dosage ratio （amount of alkalinity to ammonia ratio, mol/mol）. There is a close relationship among alkalinity, pH and the state of matter present in aqueous solution. When alkalinity was insufficient （compared to the theoretical alkalinity amount）, ammonia removal efficiency increased first and then decreased at each alkalinity dosage ratio, with an abrupt removal efficiency peak. Generally, ammonia removal efficiency rose with increasing alkalinity dosage ratio. Ammonia removal efficiency reached to 88% from 23% when alkalinity addition was sufficient. Nitrite accumulation could be achieved by inhibiting nitrite oxidizing bacteria （NOB） by free ammonia （FA） in the early period and free nitrous acid in the later period of nitrification when alkalinity was not adequate. Only FA worked to inhibit the activity of NOB when alkalinity addition was sufficient.

关键词： alkalinity nitritation coal chemical industry wastewater moving bed biofilm reactor

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A high-entropy-designed cathode with V^(5+)-V^(2+) multi-redox for high energy density sodium-ion batteries

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Journal of Energy Chemistry 2024年第10期97卷 429-437,I0008页

作者： Xiang Ding Xiaofen Yang Yibing Yang Liangwei Liu Yi Xiao Lili han College of Chemistry and Materials Science Fujian Normal University.Fuzhou 350007FujianChina State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002FujianChina

Na_(3)V_(2)(PO_(4))_(3)(NVP)is gifted with fast Na^(+)conductive NASICON *** it still suffers from low electronic conductivity and inadequate energy ***,a high-entropy modification strategy is realized by doping V^(3+)site with Ga^(3+)/Cr^(3+)/Al^(3+)/Fe^(3+)/In^(3+)simultaneously(***_(3)V_(2-x)(GaCrAlFeIn)_x(PO_(4))_(3);x=0,0.04,0.06,and 0.08)to stimulate the V^(5+)■V^(2+)reversible multi-electron *** configuration high-entropy can effectively suppress the structural collapse,enhance the redox reversibility in high working voltage(4.0 V),and optimize the electronic induced *** in-situ X-ray powder diffraction and in-situ electrochemical impedance spectroscopy tests efficaciously confirm the robust structu ral recovery and far lower polarization throughout an entire charge-discharge cycle during 1.6-4.3 V,***,the density functional theory calculations clarify the stronger metallicity of high-entropy electrode than the bare that is derived from the more mobile free electrons surrounding the vicinity of Fermi *** grace of high-entropy design and multi-electron transfer reactions,the optimal Na_(3)V_(1.7)(GaCrAlFeIn)_(0.06)(PO_(4))_(3)can exhibit perfect cycling/rate performances(90.97%@5000 cycles@30 C;112 mA h g^(-1)@10 C and 109 mA h g^(-1)@30 C,2.0-4.3 V).Furthermore,it can supply ultra-high185 mA h g^(-1)capacity with fa ntastic energy density(522 W h kg^(-1))in half-cells(1.4-4.3 V),and competitive capacity(121 mA h g^(-1))as well as energy density(402 W h kg^(-1))in full-cells(1.6-4.1 V),demonstrating enormous application potential for sodium-ion batteries.

关键词： Na_(3)V_(2)(PO_(4))_(3) High-entropy V^(5+)■V^(2+)multi-redox High energy density Sodium-ion batteries

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Large-areaβ-Ga_(2)O_(3) Schottky barrier diode and its application in DC-DC converters

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Journal of Semiconductors 2023年第7期44卷 41-44页

作者： Wei Guo Zhao han Xiaolong Zhao Guangwei Xu Shibing Long School of Microelectronics University of Science and Technology of ChinaHefei 230026China

We demonstrate superb large-area verticalβ-Ga_(2)O_(3)SBDs with a Schottky contact area of 1×1 mm^(2)and obtain a high-efficiency DC-DC converter based on the ***β-Ga_(2)O_(3)SBD can obtain a forward current of 8 A with a forward volt-age of 5 V,and has a reverse breakdown voltage of 612 *** forward turn-on voltage(VF)and the on-resistance(Ron)are 1.17 V and 0.46Ω,*** conversion efficiency of theβ-Ga_(2)O_(3)SBD-based DC-DC converter is 95.81%.This work indicates the great potential of Ga_(2)O_(3)SBDs and relevant circuits in power electronic applications.

关键词： β-Ga_(2)O_(3) SBD DC-DC converter

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Novel Organic Dyes Based on Bulky Tri（triphenylamine）-Substituted Styrene for Dye-Sensitized Solar Cells

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Chinese Journal of Chemistry 2012年第12期30卷 2779-2785页

作者： Zhang Zhiyun han Jinlong Li Xin Cai Shengyun Su Jianhua Key Laboratory for Advanced Materials and Institute of Fine Chemicals East China University of Science and Technology Shanghai 200237 China Department of Theoretical Chemistry and Biology School ofBiotechnology KTH Royal Institute of Technology SE-10691 Stockholm Sweden

Three novel donor-n-acceptor （D-π-A） metal-free organic dyes （TB, TS and TF） based on tri（triphenylamine）- substituted styrene as donor with various conjugated linkers （benzene, thiophene and furan） were synthesized, characterized and used for the application of dye-sensitized solar cells （DSSCs）. Under the same condition, The photo-to-electrical conversion efficiency of the DSSCs sensitized with TB, TS and TF reach 1.84%, 4.10% and 4.52%, respectively, which are lower than that sensitized with RI （5.02%） with one triphenylamine unit. The results suggest that these bulky donor-based sensitizers are unfavorable to DSSCs.

关键词： dye-sensitized solar cells triphenylamine styrene π-linker bulky donor

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