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UAV-assisted cooperative offloading energy efficiency system for mobile edge computing

Digital Communications and Networks 2024年第1期10卷 16-24页

作者： Xue-Yong yu Wen-Jin Niu Ye Zhu Hong-bo Zhu Jiangsu Key Laboratory of Wireless Communications Nanjing University of Posts and Telecommunications Nanjing210003China Engineering Research Centerof Health Service System Based on Ubiquitous Wireless Networks Ministry of EducationNanjng Universityof Posts and Telecommunications Nanjing210003China

Reliable communication and intensive computing power cannot be provided effectively by temporary hot spots in disaster areas and complex terrain ground *** this has greatly developed the application and integration of UAV and Mobile Edge Computing(MEC)to the Internet of Things(loT).However,problems such as multi-user and huge data flow in large areas,which contradict the reality that a single UAV is constrained by limited computing power,still *** to allowing UAV collaboration to accomplish complex tasks,cooperative task offloading between multiple UAVs must meet the interdependence of tasks and realize parallel processing,which reduces the computing power consumption and endurance pressure of *** the computing requirements of the user terminal,delay constraint of a computing task,energy constraint,and safe distance of UAV,we constructed a UAV-Assisted cooperative offloading energy efficiency system for mobile edge computing to minimize user terminal energy ***,the resulting optimization problem is originally nonconvex and thus,difficult to solve *** tackle this problem,we developed an energy efficiency optimization algorithm using Block Coordinate Descent(BCD)that decomposes the problem into three convex ***,we jointly optimized the number of local computing tasks,number of computing offloaded tasks,trajectories of UAV,and offloading matching relationship between multi-UAVs and multiuser *** results show that the proposed approach is suitable for different channel conditions and significantly saves the user terminal energy consumption compared with other benchmark schemes.

关键词： Computation offloading Internet of things(IoT) Mobile edge computing(MEC) Block coordinate descent(BCD)

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Iron oxide/CNT-based artificial nacre for electromagnetic interference shielding

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Nano Research 2024年第7期17卷 6560-6566页

作者： Cheng-Xin yu yu-Feng Meng bo Yang Jun Pang Xiang-Sen Meng Zi-Ye Zhao Qing-yue Wang Li-bo Mao Zhi-Kun Wu Shu-Hong yu Institute of Physical Science and Information Technology Anhui UniversityHefei 230601China Key Laboratory of Materials Physics Anhui Key Laboratory of Nanomaterials and NanotechnologyCAS Center for Excellence in NanoscienceInstitute of Solid State PhysicsHFIPSChinese Academy of SciencesHefei 230031China Department of Chemistry New Cornerstone Science LaboratoryInstitute of Biomimetic Materials&ChemistryAnhui Engineering Laboratory of Biomimetic MaterialsDivision of Nanomaterials&ChemistryHefei National Research Center for Physical Sciences at the MicroscaleUniversity of Science and Technology of ChinaHefei 230026China

Biological structural materials,despite consisting of limited kinds of compounds,display multifunctionalities due to their complex hierarchical *** some biomimetic strategies have been applied in artificial materials to enhance their mechanical stability,the simultaneous optimization of other functions along with the mechanical properties via biomimetic designs has not been thoroughly ***,iron oxide/carbon nanotube(CNT)-based artificial nacre with both improved mechanical and electromagnetic interference(EMI)shielding performance is fabricated via the mineralization of Fe_(3)O_(4)onto a CNTincorporated *** micro-and nano-structures of the artificial nacre are similar to those of natural nacre,which in turn improves its mechanical *** alternating electromagnetic wave-reflective CNT layers and the wave-absorptive iron oxide layers can improve the multiple reflections of the waves on the surfaces of the reflection layers,which then allows sufficient interactions between the waves and the absorption ***,compared with the reflection-dependent EMI-shielding of the non-structured material,the artificial nacre exhibits strong absorption-dependent shielding behavior even with a very low content of wave-absorptive *** to the high mechanical stability,the shielding effectiveness of the artificial nacre that deeply cut by a blade is still maintained at approximately 70%−96%depending on the incident wave *** present work provides a new way for designing structural materials with concurrently enhanced mechanical and functional properties,and a path to combine structural design and intrinsic properties of specific materials via a biomimetic strategy.

关键词： artificial nacre electromagnetic interference shielding biomineralization biomimetic material hierarchical structure

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High-sensitive nonthermally coupled upconversion for ultralow temperature sensing

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Journal of Rare Earths 2024年第11期42卷 2027-2032页

作者： Zhiyuan Cai Zhengce An Haozhang Huang yu Zhao bo Zhou State Key Laboratory of Luminescent Materials and Devices Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied Techniquesand Institute of Optical Communication MaterialsSouth China University of Technology

Upconversion based nanothermometry has received much attention due to its merits of stability,narrow band emission and rich emission ***,the previous works are mainly focused on the emissions from thermally coupled energy levels which is theoretically limited by boltzmann distribution theory with resultant low temperature sensitivity in particular at ultralow *** we report a LiYF4:Yb/Ho@LiYF4core-shell nanostructure to improve the sensitivity at low temperatures by taking advantage of non-thermally coupled energy levels of Ho3+.In detail,the green upconversion emission of Ho3+shows an increase with reducing temperature while its red upconversion emission presents a decline during the same *** is primarily due to the suppression of the non-radiative multiphonon relaxation occurred at the green emitting levels（5F4,5S2. and the intermediate level（5I6） at low *** a feature contributes to a high relative sensitivity of 7.17%/K at 11 K,much higher than reported *** results provide a promising candidate for the development of nanothermometer with high-sensitive low-temperature sensing performance.

关键词： Nanothermometry Nonthermally coupled emissions Rare earths Ultralow temperature Upconversion

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Controllable Ring-opening Polymerization ofδ-Valerolactone Catalyzed by Quinolinyl-Urea/MTBD Systems

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Chinese Journal of Polymer Science 2024年第8期42卷 1103-1110页

作者： Xin-yu Liu Liang Zhu Su-yun Jie bo-Geng Li State Key Laboratory of Chemical Engineering College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310058China

Due to their excellent biocompatibility and biodegradability,aliphatic polyesters are widely used in the biomedical,packaging and agricultural fields,which are usually accessed by the ring-opening polymerization(ROP)of lactones and the catalysts particularly play an important *** a series of quinolinyl-urea catalysts have been synthesized via the reaction between isocyanate and aminoquinoline with an amino group at different substitution positions and *** combination with 7-methyl-1,5,7-triazabicyclo[4,4,0]dec-5-ene(MTBD)as a cocatalyst and benzyl alcohol(BnOH)as an initiator,1-(3,5-bis(trifluoromethyl)phenyl)-3-(quinolin-3-yl)urea(3-QU)was observed to be most active for the ROP ofδ-valerolactone(δ-VL).The polymerization conditions were optimized by varying the type of organic base,catalyst concentration and reaction *** changing the ratio of[M]_0/[I],linear polyvalerolactones(PVLs)with different molecular weights and narrow molecular weight distribution were *** kinetic and chain extension experiments were carried out to prove the"living"/controllable *** the NMR experiments were used to support the proposal of possible mechanism.

关键词： Quinolinyl-urea Ring-opening polymerization PVL

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Reducing Subspaces of Toeplitz Operators Induced by a Class of Non-analytic Monomials over the Unit Ball

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Acta Mathematica Sinica,English Series 2024年第7期40卷 1767-1777页

作者： Yan yue SHI bo ZHANG Xu TANG yu Feng LU School of Mathematical Sciences Ocean University of ChinaQingdao 266100P.R.China School of Mathematics and Information Sciences Yantai UniversityYantai 264005P.R.China School of Mathematical Sciences Space Engineering UniversityBeijing 101416P.R.China School of Mathematical Sciences Dalian University of TechnologyDalian 116024P.R.China

In this paper,we describe the minimal reducing subspaces of Toeplitz operators induced by non-analytic monomials on the weighted Bergman spaces and Dirichlet spaces over the unit ball B_(2..It is proved that each minimal reducing subspace M is finite dimensional,and if dim M≥3,then M is induced by a ***,the structure of commutant algebra v(T_(w)N_(z)N):={M^(*)_(w)NM_(z)N,M^(*)_(z)NM_(w)N}′is determined by N and the two dimensional minimal reducing subspaces of(T_(w)N_(z)*** also give some interesting examples.

关键词： Reducing subspace operator-weighted shifts Toeplitz operator von Neumann algebra

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Recent advances and challenges of nitrogen/nitrate electro catalytic reduction to ammonia synthesis

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Frontiers in Energy 2024年第2期18卷 128-140页

作者： Junwen CAO Yikun HU yun ZHENG Wenqiang ZHANG bo yu Institute of Nuclear and New Energy Technology(INET) Collaborative Innovation Center of Advanced Nuclear Energy TechnologyTsinghua UniversityBeijing 100084China Department of Chemical Engineering University of WaterlooWaterlooOntario N2L 3G1Canada Institute of New Energy Materials and Engineering School of Materials Science and EngineeringFuzhou UniversityFuzhou 350108China

The Haber-bosch process is the most widely used synthetic ammonia technology at *** its invention,it has provided an important guarantee for global food ***,the traditional Haber-bosch ammonia synthesis process consumes a lot of energy and causes serious environmental *** the serious pressure of energy and environment,a green,clean,and sustainable ammonia synthesis route is urgently *** synthesis of ammonia is a green and mild new method for preparing ammonia,which can directly convert nitrogen or nitrate into ammonia using electricity driven by solar,wind,or water energy,without greenhouse gas and toxic gas ***,the basic mechanism of the nitrogen reduction reaction(NRR)to ammonia and nitrate reduction reaction(NO_(3)^(-))to ammonia were *** representative approaches and major technologies,such as lithium mediated electrolysis and solid oxide electrolysis cell(SOEC)electrolysis for NRR,high activity catalyst and advanced electrochemical device fabrication for(NO_(3)^(-))RR and electrochemical ammonia synthesis were *** on the above discussion and analysis,the main challenges and development directions for electrochemical ammonia synthesis were further proposed.

关键词： electrochemical ammonia synthesis nitrogen nitrate nitrogen reduction reaction(NRR)to ammonia nitrate reduction reaction(NO_(3)^(-))RR

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BL03HB: a Laue microdiffraction beamline for both protein crystallography and materials science at SSRF

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Nuclear Science and Techniques 2024年第7期35卷 68-78页

作者： Zhi-Jun Wang Si-Sheng Wang Zheng-Huang Su Li yu yu-Zhu Wang bo Sun Wen Wen Xing-yu Gao Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai201210China University of Chinese Academy of Science Beijing100049China

A Laue microdiffraction beamline(BL03HB) was constructed at the Shanghai Synchrotron Radiation Facility(SSRF).This beamline features two consecutive focusing points in two different sectors within its end station, the first dedicated to protein crystallography and the other tailored to materials science applications. Based on a superbend dipole magnet with a magnetic field of 2.2. T, a two-stage focusing design was implemented with two sets of Kirkpatrick-Baez mirrors to achieve a micro white beam as small as 4.2.μ m ×4.3 μ m at the first sector and 0.9 μ m ×1.3 μ m at the second sector in the standard beamline operation mode at SSRF. The X-ray microbeam in the two sectors can be easily switched between monochromatic and white beams by moving a four-bounce monochromator in or out of the light path, respectively. In the protein crystallography sector, white-beam Laue microdiffraction was demonstrated to successfully determine the structure of protein crystals from only a few images of diffraction data collected by a Pilatus 2.M area detector. In the materials science sector,the white-beam Laue diffraction was collected in a reflection geometry using another Pilatus 2.M area detector, which could map the microstructural distribution on the sample surface by scanning the samples. In general, the BL03HB beamline promotes the application of Laue microdiffraction in both protein crystallography and materials science. This paper presents a comprehensive overview of the BL03HB beamline, end station, and the first commission results.

关键词： Crystallography White-beam Laue microdiffraction Beamline Synchrotron

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Biomimetic chitin hydrogel via chemical transformation

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Nano Research 2024年第2期17卷 771-777页

作者： Rui-Rui Liu Qian-Qian Shi yu-Feng Meng Yong Zhou Li-bo Mao Shu-Hong yu Division of Nanomaterials&Chemistry Hefei National Research Center for Physical Sciences at the MicroscaleDepartment of ChemistryInstitute of Biomimetic Materials&ChemistryAnhui Engineering Laboratory of Biomimetic MaterialsUniversity of Science and Technology of ChinaHefei 230026China College&Hospital of Stomatology Key Laboratory of Oral Diseases Research of Anhui ProvinceAnhui Medical UniversityHefei 230032China Department of Dental Implantology College&Hospital of StomatologyAnhui Medical UniversityHefei 230032China

Chitin hydrogel has been recognized as a promising material for various biomedical applications because of its biocompatibility and ***,the fabrication of strong chitin hydrogel remains a big challenge because of the insolubility of chitin in many solvents and the reduced chain length of chitin regenerated from *** herein introduce the fabrication of chitin hydrogel with biomimetic structure through the chemical transformation of chitosan,which is a water-soluble deacetylated derivative of *** reacetylation of the amino group in chitosan endows the obtained chitin hydrogel with outstanding resistance to swelling,degradation,extreme temperature and pH conditions,and organic *** chitin hydrogel has excellent mechanical properties while retaining a high water content(more than 95 wt.%).It also shows excellent antifouling performance that it resists the adhesion of proteins,bacteria,blood,and ***,as the initial chitosan solution can be feasibly frozen and templated by ice crystals,the chitin hydrogel structure can be either nacre-like or wood-like depending on the freezing method of the precursory chitosan *** to these anisotropic structures,such chitin hydrogel can exhibit anisotropic mechanics and mass transfer *** current work provides a rational strategy to fabricate chitin hydrogels and paves the way for its practical applications as a superior biomedical material.

关键词： chitin hydrogel biomimetic structure chemical stability mechanical strength antifouling

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Synergistic strengthening mechanism of Ca^(2.)-sodium silicate to selective separation of feldspar and quartz

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International Journal of Minerals,Metallurgy and Materials 2024年第9期31卷 1985-1995页

作者： bo Lin Jingzhong Kuang Yiqiang Yang Zheyu Huang Delong Yang Mingming yu School of Resources and Environmental Engineering Jiangxi University of Science and TechnologyGanzhou 341000China Jiangxi Key Laboratory of Mining Engineering Ganzhou 341000China

Inhibitors are important for flotation separation of quartz and *** this study,a novel combined inhibitor was used to separate quartz and feldspar in near-neutral *** inhibition of the combined inhibitor was assessed by micro-flotation *** a series of detection methods were used to detect differences in the surface properties of feldspars and quartz after flotation reagents and put forward the synergistic strengthening *** outcomes were pointed out that pre-mixing combined inhibitors were more effective than the addition of Ca^(2.)and SS in sequence under the optimal proportion of 1:5.A concentrate from artificial mixed minerals that was characterized by a high quartz grade and a high recovery was acquired,and was found to be 90.70wt% and 83.70%,*** was demonstrated that the combined inhibitor selectively prevented the action of the collector and feldspar from Fourier-transform infrared(FT-IR)and adsorption capacity *** results of X-ray photoelectron spectroscopy(XPS)indicated that Ca^(2.)directly interacts with the surface of quartz to increase the adsorption of *** contrast,the chemistry property of Al on the feldspar surface was altered by combined inhibitor due to Na^(+)and Ca^(2.)taking the place of K^(+),resulting in the composite inhibitor forms a hydrophilic structure,which prevents the adsorption of the collector on the surface of feldspar by interacting with the Al active *** combination of Ca^(2.)and SS synergically strengthens the difference of collecting property between quartz and feldspar by collector,thus achieving the effect of efficient separation.A new strategy for flotation to separate quartz from feldspar in near-neutral pulp was provided.

关键词： feldspar quartz Ca^(2.)-sodium silicate selective adsorption flotation separation

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Adsorptive interaction between typical VOCs and various topological zeolites:Mixture effect and mechanism

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Journal of Environmental Sciences 2024年第2期136卷 626-636页

作者： bo yu Hua Deng yuqin Lu Tingting Pan Wenpo Shan Hong He Center for Excellence in Regional Atmospheric Environment and Key Laboratory of Urban Pollutant Conversion Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China University of Chinese Academy of Sciences Beijing 100049China State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China

Adsorption is one of the most feasible and effective methods to alleviate the volatile organic compounds(VOCs)***,the mixture effect and mechanism for competitive adsorption of VOCs on zeolites are barely *** this study,toluene,acetone,and ethyl acetate as prevalent VOCs species were removed by four potential zeolites(13X,USY,Beta,ZSM-5)in both single-and multi-component *** structure-property relationship between adsorbate-adsorbent pairs was revealed by X-ray diffraction,scanning electron microscopy,energy dispersive spectrometer,X-ray fluorescence,N_(2. adsorption and density function theory *** molecular polarity and volatility of VOCs species played key roles in adsorption and the dynamic uptakes were generally listed as follows:ethyl acetate>toluene>*** for the above VOCs mixtures,13X zeolite selectively adsorbed oxygenated VOCs rather than *** contrast,USY exhibited a preference to trap *** acetate could be readily enriched by ZSM-5 and Beta *** possible explanations and implications are discussed based on the subtle change in electron *** results obtained are vital for understanding the mixture effect of VOCs adsorption and may guide the selection of proper adsorbent for real applications.

关键词： Adsorption Zeolites VOCs Mixture effect DFT

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