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Nano Research 2022年第10期15卷 8677-8687页

作者： Maofan Zhou Xuefei Xu Gengping Wan Pengpeng Mou Shengjie Teng Guizhen Wang State Key Laboratory of Marine Resource Utilization in South China Sea Hainan UniversityHaikou 570228China

With the increasingly severe electromagnetic interference issue and the huge heat dissipation demand caused by the miniaturized and integrated electronic devices,exploring the heat-conduction microwave absorption(MA)materials is highly desired and remains a great challenge.Herein,we reported the fabrication of ZnO/amorphous carbon(ZnO/AC)hybrid films covered on the surface of graphene(ZnO/AC/Graphene)to simultaneously apply as the MA and thermal management materials.The ZnO/AC coatings synthesized with the auxiliary of an atomic layer deposition(ALD)method are highly uniform and controllable,which can significantly improve the MA performance and thermal conduction properties of graphene.The reflection loss(RL)of−55.4 dB and the effective absorption bandwidth of 5.3 GHz were achieved with thickness of 2.0 mm for ZnO/AC/Graphene at a low loading content(3 wt.%).The minimum RL of−57.9 dB can be obtained in the ZnO/AC/Graphene composites at a low frequency(7.8 GHz).Moreover,the absorption frequency can be regulated by changing the ZnO/AC which can be readily implemented by adjusting the ALD cycles of ZnO.The thermal conductivity of ZnO/AC/Graphene is up to 257.8 mW·m^(−1)·K^(−1),increased by 53.2%compared with natural rubber.The enhancement mechanisms of microwave loss and heat conduction are systematically studied in detail.This work not only develops an excellent candidate,but also provides a novel strategy to design functional materials for heat-conduction MA application.

关键词： atomic layer deposition graphene microwave absorption heat conductivity

QBFO-BOMP Based Channel Estimation Algorithm for mmWave Massive MIMO Systems

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Computer Modeling in Engineering & Sciences 2023年第11期137卷 1789-1804页

作者： Xiaoli Jing Xianpeng Wang Xiang Lan Ting Su State Key Laboratory of Marine Resource Utilization in South China Sea and School of Information and Communication Engineering Hainan UniversityHaikou570228China

At present,the traditional channel estimation algorithms have the disadvantages of over-reliance on initial conditions and high complexity.The bacterial foraging optimization(BFO)-based algorithm has been applied in wireless communication and signal processing because of its simple operation and strong self-organization ability.But the BFO-based algorithm is easy to fall into local optimum.Therefore,this paper proposes the quantum bacterial foraging optimization(QBFO)-binary orthogonal matching pursuit(BOMP)channel estimation algorithm to the problem of local optimization.Firstly,the binary matrix is constructed according to whether atoms are selected or not.And the support set of the sparse signal is recovered according to the BOMP-based algorithm.Then,the QBFO-based algorithm is used to obtain the estimated channel matrix.The optimization function of the least squares method is taken as the fitness function.Based on the communication between the quantum bacteria and the fitness function value,chemotaxis,reproduction and dispersion operations are carried out to update the bacteria position.Simulation results showthat compared with other algorithms,the estimationmechanism based onQBFOBOMP algorithm can effectively improve the channel estimation performance of millimeter wave(mmWave)massive multiple input multiple output(MIMO)systems.Meanwhile,the analysis of the time ratio shows that the quantization of the bacteria does not significantly increase the complexity.

关键词： Channel estimation bacterial foraging optimization quantum bacterial foraging optimization binary orthogonal matching pursuit massive MIMO

Eukaryotic food sources analysis in situ of tropical common sea cucumber Holothuria leucospilota based on 18S rRNA gene high-throughput sequencing

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Journal of Oceanology and Limnology 2023年第3期41卷 1173-1186页

作者： Yue ZHANG Fei GAO Qiang XU Yanan WANG Haiqing WANG Aimin WANG State Key Laboratory of Marine Resource Utilization in South China Sea Hainan UniversityHaikou 570228China College of marine Science Hainan UniversityHaikou 570228China

sea cucumber Holothuria leucospilota is one of the most widespread tropical holothurian species.In this study,eukaryotic organism composition in foregut and hindgut contents of H.leucospilota and surrounding sediments was assessed by 18S rRNA gene high-throughput sequencing.Eukaryon richness and diversity in the habitat sediments were significantly higher than those in foregut and hindgut contents of the sea cucumbers(Pmarine sediment group sequences were respectively assigned to 18.20±1.32,19.40±1.03,and 21.80±0.37 phyla.In the foregut contents,Nematoda(20.18%±9.59%),Mollusca(16.12%±10.49%),Chlorophyta(10.04%±4.85%),Annelida(8.72%±10.93%),Streptophyta(8.46%±4.65%),and Diatomea(5.99%±2.01%)were the predominant phyla,which showed the eukaryotic food sources of H.leucospilota were primarily belong to the above phyla.The predominant phyla in the hindgut contents were Streptophyta(45.55%±17.32%),Mollusca(4.93%±4.82%),Arthropoda(5.37%±3.08%),Diatomea(3.88%±2.34%),and Chlorophyta(3.79%±1.59%);and Annelida(37.80%±17.00%),Arthropoda(24.49%±12.53%),Platyhelminthes(7.14%±3.02%),Nematoda(4.14%±0.91%),and Diatomea(5.11%±1.35%)had large contents in the sediments.The comparatively high content of Paris genus in phylum Streptophyta in foregut contents indicated that land plants were one of the primary food sources of H.leucospilota,however the significantly higher contents of Streptophyta in hindgut contents than that in foregut contents might suggest a large part of the terrigenous detritus ingested might not be digested by H.leucospilota.UPGMA and PCoA analysis revealed that eukaryotic organism composition differed significantly between foregut contents of H.leucospilota and ambient sediments,indicating selective feeding feature of H.leucospilota.This study provided useful references for artificial feed of tropical sea cucumbers and enhanced understanding of the ecological roles of detritus-feeding macrobenthos.

关键词： Holothuria leucospilota food source 18S rRNA gene gut content sediment

Iterative Interference Cancellation for Non-orthogonal Multiple Access System

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Chinese Journal of Electronics 2020年第3期29卷 540-546页

作者： CHEN Min YANG Yongqin School of Information and Communication Engineering Hainan University State Key Laboratory of Marine Resource Utilization in South China Sea

Non-orthogonal multiple access(NOMA)makes multiple users to overload the same wireless resources by utilizing the superposition coding principle,so that it can improve the system capacity and spectral efficiency. Various NOMA schemes are proposed, including the Power-domain NOMA(PD-NOMA). Most of them are using Successive interference cancellation(SIC) for detection, which limits the promised performance gain brought by NOMA due to the error propagation. An Iterative SIC and parallel interference cancellation(ISP)method is proposed for the PD-NOMA system. The MaxLog-MAP(MLM) algorithm(MAP is short for Maximum a posteriori) and SIC are used for performance comparison.Simulation results show that the Bit error rate(BER)performance of ISP is much better than that of SIC,and is close to that of MLM. It can perform even better than MLM at low signal to noise ratio for the user with lower power allocation. The ISP can obtain the promised performance gain brought by NOMA.

关键词： Non-orthogonal multiple access Successive interference cancellation(SIC) Iterative SIC and parallel interference cancellation Max-Log-MAP

One-dimensional PtFe hollow nanochains for the efficient oxygen reduction reaction

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Carbon Energy 2022年第6期4卷 1003-1010页

作者： Peng Rao Junming Luo Jing Li Wei Huang Wei Sun Qi Chen Chunman Jia Zhongxin Liu Peilin Deng Yijun Shen Xinlong Tian State Key Laboratory of Marine Resource Utilization in South China Sea Hainan Provincial Key Lab of Fine ChemistrySchool of Chemical Engineering and TechnologyHainan UniversityHaikouChina

Integration of electronic and strain effects with tailored structures is significant to tuning the electrocatalytic activity and stability of the electrocatalysts for the oxygen reduction reaction(ORR).In this study,onedimensional PtFe hollow nanochains are synthesized by a facile and effective method,which exhibit a highly open and porous structure.The modulated electronic and strain effects of Pt atoms are verified by extensive structural characterizations,and the mass and specific activities of the prepared catalyst are roughly 7.45 and 12.44 times higher than those of the commercial Pt/C catalyst,respectively.Remarkably,the catalyst demonstrates robust performance with negligible activity decay after an accelerated durability test for 30,000 cycles.The high activity of the catalyst is probably due to the optimized absorption affinity of Pt-O accelerating the reaction kinetics induced by the cooperation of Fe atoms as well as the unique hollow and curved structures.This study provides new insights into the rational design of high-performance ORR catalysts with considerable durability.

关键词： electrocatalysts hollow nanochains one-dimensional oxygen reduction reaction zinc-air battery

Rational design ternary platinum based electrocatalysts for effective methanol oxidation reaction

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Journal of Energy Chemistry 2022年第7期31卷 230-235,I0007页

作者： Hao Tian Daoxiong Wu Jing Li Junming Luo Chunman Jia Zhongxin Liu Wei Huang Qi Chen Chong Michael Shim Peilin Deng Yijun Shen Xinlong Tian State Key Laboratory of Marine Resource Utilization in South China Sea Hainan Provincial Key Lab of Fine ChemistrySchool of Chemical Engineering and TechnologyHainan UniversityHaikou 570228HainanChina

Exploring effective, durable, and affordable electrocatalysts of methanol oxidation reaction(MOR) is of vital significance for the industrial application of direct methanol fuel cells. Herein, an efficient, general,and expandable method is developed to synthesis two-dimensional(2D) ternary Pt Bi M nanoplates(NPLs), in which various M(Co, Ni, Cu, Zn, Sn) is severed as the third component to the binary Pt Bi system. The MOR performance of Pt Bi M NPLs is entirely investigated, demonstrating that both the MOR activity and durability is enhanced with the introduction of the additional composition. Pt3Bi3Zn NPLs shows much higher MOR activity and stability than that of the Pt Bi counterparts, not to mention the current advanced Pt Ru/C and Pt/C catalysts. The prominent performances are attributed to the modulated electronic structure of the surface Pt in Pt Bi NPLs by the addition of Zn, resulting in a weakened affination between Pt and the adsorbed poisoning species(mainly CO) compared with Pt Bi NPLs, verified by density functional theory(DFT) calculations. In addition, the absorbed OH can be generated on the surface of Zn atom due to its favorable water activation properties, thus the CO removal on the adjacent Pt atoms is accelerated, further leading to a high activity and anti-poisoning performance of the resulting Pt_(3)Bi_(3)Zn catalyst. This work provides new insights and robust strategy for highly efficient MOR electrocatalyst with extraordinary anti-poisoning performance and stability.

关键词： Fuel cells Ternary nanoplates Durability Methanol oxidation reaction Anti-poisoning

Three-dimensional flexible Au nanoparticles-decorated TiO_(2) nanotube arrays for photoelectrochemical biosensing

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Journal of Materials Science & Technology 2020年第21期56卷 162-169页

作者： Xidong Zhang Dong Yue Ling Zhang Shiwei Lin State Key Laboratory of Marine Resource Utilization in South China Sea School of Materials Science and EngineeringHainan UniversityHaikou 570228China

Controlling the charge transfer and thus enhancing the excitons’lifetime are the key to the realization of efficient photoelectrochemical(PEC)devices.Moreover,fabrication of flexible and collapsible sensors can greatly facilitate the implementation of smart PEC sensing devices into practical applications.Herein,we sagely designed and successfully fabricated three-dimensional flexible Au nanoparticles-decorated TiO_(2) nanotube arrays(Au@TiO2)for the efficient PEC biosensing of glucose.The Schottky barrier derived from the Au@TiO2 heterostructure efficiently separates the charge carriers at the junction interfaces,thus greatly increasing the concentration and lifetime of holes left in the valence band of TiO2.The separated holes further evidently generate the active hydroxyl radicals,which can specifically recognize and oxidize glucose.As a result,Au@TiO_(2) exhibits excellent photoelectric activity and selectivity,far superior to TiO_(2) without decorated Au nanoparticles.In addition,such asymmetric Au@TiO_(2) system has been proved to feature the intrinsic flexibility nature,since its PEC biosensing performance is almost unaffected under indirect light irradiation and serious tensile strain.

关键词： Photoelectrochemical biosensing Metal/semiconductor interface Flexibility TiO_(2)nanotube arrays

Coupling interface constructions of FeOOH/NiCo_(2)S_(4)by microwave-assisted method for efficient oxygen evolution reaction

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Rare Metals 2023年第6期42卷 1847-1857页

作者： Ming-Liang Guo Zhi-Yu Wu Miao-Miao Zhang Zi-Jian Huang Ke-Xi Zhang Bing-Rong Wang Jin-Chun Tu state key laboratory of marine resource utilization in the south china sea College of Materials Science and EngineeringHainan UniversityHaikou570228China School of Science Hainan UniversityHaikou570228China

The oxygen evolution reaction(OER) with slow kinetics is the rate-limiting step of electrochemical water splitting.A reasonable construction of interface nanostructures is the key to improving the OER efficiency and durability of non-noble metal electrocatalysts.In this study,a FeOOH/NiCo_(2)S_(4) core-shell nanorod array with abundant heterogeneous interfaces and high density of active sites was successfully prepared by a microwave-as sis ted method.Experimental research and theoretical calculations show that the abundant strong coupling Ni/Co-S-Fe interface helps in adjusting the electronic structure of the material surface,optimizing the adsorption energy of the intermediate,and realizing an efficient catalytic process.The as-synthesized FeOOH/NiCo_(2)S_(4)/NF composite electrode exhibited lower overpotential(198 mV) and Tafel slope(62 mV·dec^(-1)) at a current density of 10 mA·cm^(-2)and excellent stability(approximately 100% retention after100 h) than the NiCo_(2)S_(4)/nickel foam(NF).In conclusion,constructing heterojunctions with complementary active materials is an effective strategy to design efficient and robust OER electrocatalysts.

关键词： Transition metal sulfides FeOOH Interface structure Adsorption energy Oxygen evolution

Plasma induced grain boundaries to boost electrochemical reduction of CO2 to formate

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Journal of Energy Chemistry 2024年第8期95卷 636-643页

作者： Guan Wang Shengtao Zhong Xiaoqian Xiong Jing Li Fangyuan Wang Li Huo Daoxiong Wu Xingqi Han Zhitong Wang Qi Chen Xinlong Tian Peilin Deng Hainan University School of marine Science and Engineering State Key Laboratory of Marine Resource Utilization in South China Sea

Bismuth-based catalysts are highly promising for the electrochemical carbon dioxide reduction reaction(eCO2RR) to formate product.However,achieving high activity and selectivity towards formate and ensuring long-term stability remains challenging.This work reports the oxygen plasma inducing strategy to construct the abundant grain boundaries of Bi/BiOxon ultrathin two-dimensional Bi nanosheets.The oxygen plasma-treated Bi nanosheet(OP-Bi) exhibits over 90% Faradaic efficiency(FE) for formate at a wide potential range from-0.5 to-1.1 V,and maintains a great stability catalytic performance without significant decay over 30 h in flow cell.Moreover,membrane electrode assembly(MEA) device with OPBi as catalyst sustains the robust current density of 100 mA cm-2over 50 h,maintaining a formate FE above 90%.In addition,rechargeable Zn-CO2battery presents the peak power density of1.22 mW cm-2with OP-Bi as bifunctional catalyst.The mechanism experiments demonstrate that the high-density grain boundaries of OP-Bi provide more exposed active sites,faster electron transfer capacity,and the stronger intrinsic activity of Bi atoms.In situ spectroscopy and theo retical calculations further elucidate that the unsaturated Bi coordination atoms between the grain boundaries can effectively activate CO2molecules through elongating the C-O bond,and reducing the formation energy barrier of the key intermediate(~*OCOH),thereby enhancing the catalytic performance of eCO2RR to formate product.

关键词： Bi nanosheet CO2 electroreduction Grain boundary MEA device Unsaturation Bi atoms

Study of the wind-pressure distribution of flat-roof parabolic condensers based on wind-tunnel tests

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Clean Energy 2022年第6期6卷 893-906页

作者： Qiong Zou Xuan Zeng Chao Wang Yijun Shen College of Civil Engineering and Mechanics Xiangtan UniversityXiangtanHunan Province 411105China State Key Laboratory of Marine Resource Utilization in South China Sea Hainan UniversityHaikou 570228China

The structure of parabolic condensers makes them susceptible to wind load because of their thin and large windward mirrors.In this paper,the wind pressure on a model of a condenser mirror(1:35)on multistorey flat roofs is analysed via pressure measurement in a wind tunnel.The mean wind-pressure distribution law of flat-roof condenser mirrors(including the change law with working conditions and the maximum distribution characteristics)and the distribution law of fluctuating and extreme wind pressure are obtained.Furthermore,by comparison with the ground-based condenser distribution law,similarities and differences between the two are obtained.Research results show that the wind-pressure distribution law of flat-roof parabolic condenser mirrors is the same as those on the ground,but the mean wind-pressure coefficient(absolute value)is generally~30%smaller.Furthermore,the maximum effect is generally located at the windward mirror edge and the mirror is more susceptible to wind pressure in wind directions of 30°and 135°-150°.The results of this study can provide a theoretical reference for wind-resistant structure design and multistorey flat-roof condenser-related research.

关键词： parabolic condenser flat roof of multistorey building wind-tunnel tests mean wind pressure fluctuating wind pressure extreme wind pressure concentrated solar energy