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China Communications 2024年第3期21卷 205-216页

作者： Zhang Yue zheng Fuchun Luo Jingjing school of Electronic and Information engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China

Due to the limited uplink capability in heterogeneousnetworks (HetNets), the decoupled uplinkand downlink access (DUDA) mode has recently beenproposed to improve the uplink performance. In thispaper, the random discontinuous transmission (DTX)at user equipment (UE) is adopted to reduce the interferencecorrelation across different time slots. By utilizingstochastic geometry, we analytically derive themean local delay and energy efficiency (EE) of an uplinkHetNet with UE random DTX scheme under theDUDA mode. These expressions are further approximatedas closed forms under reasonable *** results reveal that under the DUDA mode, there isan optimal EE with respect to mute probability underthe finite local delay constraint. In addition, with thesame finite mean local delay as under the coupled uplinkand downlink access (CUDA) mode, the HetNetsunder the DUDA mode can achieve a higher EE witha lower mute probability.

关键词： decoupled uplink and downlink access(DUDA) heterogeneous networks(HetNets) random discontinuous transmission(DTX) stochastic geometry

Pseudo-dynamic testing of a fabricated composite frame with steel plate shear walls

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Journal of Zhejiang University-science A(Applied Physics & engineering) 2017年第6期18卷 454-466页

作者： zheng-gang CAO Peng DU Feng FAN Zhe-ming CHEN Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of Technology Harbin 150090 China school of Civil engineering Harbin Institute of Technology Harbin 150090 China Shanghai Municipal engineering Design institute (Group) Co. Ltd Shanghai 200092 China

A pseudo-dynamic testing program was generated on a fabricated composite frame with steel plate shear walls （SPSWs） to study its seismic perlbrmance. The specimen was a three-storey single-bay frame, which was composed of H- section steel columns and composite beams, and was assembled by bolted height-adjustable steel beam-to-column connections （BHA connections）. Beam-only-connected SPSWs were selected as lateral load resisting members. The specimen was subjected to four ground motions of progressively increasing intensity. The results showed that：（1） beam-only-connected S PSWs provided sufficient lateral load resistance, lateral stiffness, and energy dissipation capacity to the fabricated frame via the tension ficld action developed in their infill panels; （2） the fabricated frame, assembled by BHA connections, exhibited substantial redundancy and good ductility; （3） an undesirable failure mode of the fabricated frame, in huge earthquakes, included severe cracking in composite beams and block shear failure in SPSWs＇ connections; （4） the inter-storey shear force distribution determined by ASCE/SE1 7-10 was verified with experimental data.

关键词： Fabricated frame Composite beam Steel plate shear walls Pseudo-dynamic test

Facile low-temperature supercritical carbonization method to prepare high-loading nickel single atom catalysts for efficient photodegradation of tetracycline

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Journal of Environmental sciences 2024年第4期138卷 373-384页

作者： Han Qiao Lirong zheng Shiwen Hu Gang Tang Hongri Suo Chongxuan Liu school of Environment Harbin Institute of TechnologyHarbin 150090China State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control School of Environmental Science and EngineeringSouthern University of Science and TechnologyShenzhen 518055China Beijing Synchrotron Radiation Facility(BSRF) Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China

Environmental photocatalysis is a promising technology for treating antibiotics in *** this study,a supercritical carbonization method was developed to synthesize a single-atom photocatalyst with a high loading of Ni(above 5 wt.%)anchored on a carbonnitrogen-silicate substrate for the efficient photodegradation of a ubiquitous environmental contaminant of tetracycline(TC).The photocatalyst was prepared from an easily obtained metal-biopolymer-inorganic supramolecular hydrogel,followed by supercritical drying and carbonization *** low-temperature(300℃)supercritical ethanol treatment prevents the excessive structural degradation of hydrogel and greatly reduces the metal clustering and aggregation,which contributed to the high Ni *** characterizations confirmed that Ni was present at isolated sites and stabilized by Ni-N and Ni-O bonds in a Ni-(N/O)_(6)-C/SiC configuration.A 5%Ni-C-Si catalyst,which performed the best among the studied catalysts,exhibited a wide visible light response with a narrow bandgap of 1.45 eV that could efficiently and repeatedly catalyze the oxidation of TC with a conversion rate of almost 100% within 40 *** reactive species trapping experiments and electron spin resonance(ESR)tests demonstrated that the h+,and·O_(2)-were mainly responsible for TC *** TC degradation mechanism and possible reaction pathways were provided ***,this study proposed a novel strategy to synthesize a high metal loading singleatom photocatalyst that can efficiently remove TC with high concentrations,and this strategy might be extended for synthesis of other carbon-based single-atom catalysts with valuable properties.

关键词： Carbon-based single-atom catalyst Nickel Photocatalytic degradation Tetracycline Visible light

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考虑热效应的空化流动研究进展

力学学报 2024年第8期56卷 2165-2183页

作者：马静雯王诗平杨英狄郑智颖熊骋望哈尔滨工程大学船舶工程学院哈尔滨150001 哈尔滨工业大学能源科学与工程学院哈尔滨150001

高速航行体的多相水动力学过程,如水下发射与超空泡航行等,在通入高温气体形成空泡的过程中需考虑热效应对空泡动力学的影响.且火箭低温液态燃料供应及核反应堆高温管道输送等工程问题中发生的空化现象也具有显著的热效应.在以上流动中... 详细信息

高速航行体的多相水动力学过程,如水下发射与超空泡航行等,在通入高温气体形成空泡的过程中需考虑热效应对空泡动力学的影响.且火箭低温液态燃料供应及核反应堆高温管道输送等工程问题中发生的空化现象也具有显著的热效应.在以上流动中,热效应不仅仅会改变流体的物理性质,影响相间质量输运和热传递,还会引发复杂的动力学和热力学变化,因此考虑热效应的空化机理、能量的传递和输运规律以及流动不稳定性机理是亟需解决的关键科学问题.文章基于不同影响因素将考虑热效应的空化流动分为高温壁面空化、高温通气空泡、高温水空化以及低温热敏流体空化,并分别综述了4类情况下空泡演化特性和影响规律.此外,总结归纳了数值模拟考虑热效应的空化流动常用的空化模型和湍流模型,以及在实验研究中采用的各种多物理场测量技术,但相关数值仿真和实验技术还有待进一步发展完善.未来还需深入研究热效应对空化流动生成和稳定性的影响机制,全面了解和掌握热效应空化流动的特点和行为,为相关领域的工程设计和优化提供更加准确的数据支撑、分析工具和理论基础.

关键词：热效应空化流动多相流多物理场

Self-assembly tungsten selenide hybrid ternary MOF derived magnetic alloys via multi-polarization to boost microwave absorption

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Nano Research 2024年第3期17卷 1625-1635页

作者： Tianbao Zhao Tingting zheng Di Lan Yan Zhang zhengshuo Sun Chao Wang Zirui Jia Guanglei Wu institute of Materials for energy and Environment State Key Laboratory of Bio-fibers and Eco-textilesCollege of Materials Science and EngineeringQingdao UniversityQingdao 266071China school of Materials science and engineering Hubei University of Automotive TechnologyShiyan 442002China College of Chemistry and Chemical engineering Qingdao UniversityQingdao 266071China

Confronted with severe electromagnetic wave pollution,the development of high-performance electromagnetic wave shielding or absorbing materials is an effective way to deal with ***,double transition metal alloys and transition metal dichalcogenides have attracted extensive attention in electromagnetic wave absorption,but few reports have studied the effects of these two materials on electromagnetic wave absorption at the same *** this work,cobalt-based alloy with magnetic loss mechanism was selected for composition *** ternary metal-organic framework was prepared by the one-step method,and then CoCu/C was prepared by high temperature ***,in the hydrothermal process,ultra-thin tungsten selenide nanosheets were coated on the surface of magnetic component,and the final polyhedral WSe_(2)/CoCu/C composites with multiple heterogeneous interfaces were *** synergistic effect of dielectric and magnetic components optimizes impedance matching and allows more electromagnetic waves to enter the ***,through the conduction loss of high conductivity graphitized carbon,interfacial polarization,and dipole polarization of heterogeneous interfaces between the components,the magnetic loss provided by CoCu alloy can work together to maximize the attenuation ability of electromagnetic ***,the minimum reflection loss(RLmin)value of the composite reaches-53.43 dB when the matched thickness is 2.1 mm,while the maximum effective absorption bandwidth(EABmax)reaches 6.0 GHz at a thin thickness of 1.8 *** work provides some support and reference for the design of novel electromagnetic wave absorbing materials via the dielectric/magnetic loss synergistic mechanism.

关键词： metal-organic framework dielectric/magnetic loss transition metal dichalcogenide electromagnetic wave absorption

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轻骨料性能对界面区微观结构的影响

沈阳建筑大学学报（自然科学版） 2009年第6期25卷 1120-1124页

作者：董淑慧张宝生葛勇郑秀华哈尔滨工业大学交通科学与工程学院黑龙江哈尔滨150090

目的研究不同吸水率轻骨料制备的混凝土中骨料-水泥石界面区的微观形貌、水化产物的钙硅质量比、水泥石的显微硬度以及孔结构等性能参数．方法采用扫描电镜（SEM）、X射线能谱分析（EDXA）、显微硬度以及孔结构等试验手段，并与普通骨... 详细信息

目的研究不同吸水率轻骨料制备的混凝土中骨料-水泥石界面区的微观形貌、水化产物的钙硅质量比、水泥石的显微硬度以及孔结构等性能参数．方法采用扫描电镜（SEM）、X射线能谱分析（EDXA）、显微硬度以及孔结构等试验手段，并与普通骨料混凝土进行对比分析．结果轻骨料-水泥石界面区各项性能均优于普通骨料，轻骨料吸水率越大、表面越粗糙，界面区水泥石结构越致密，孔结构呈细化趋势，低、中、高吸水率轻骨料-水泥石界面区显微硬度较普通骨料分别提高15．8％、79．6％和96．3％，界面增强层厚度为40～60μm，并且，中、高吸水率陶粒混凝土中，距骨料-水泥石界面-10～0μm范围内具有一个明显的内增强层．结论轻骨料性能对界面区水泥石微观结构具有显著影响，中、高吸水率轻骨料可使界面区结构得以改善．

关键词：轻骨料吸水率界面过渡区微观结构

Numerical multi-physical optimization of operating condition and current collecting setup for large-area solid oxide fuel cells

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Frontiers in energy 2024年第3期18卷 356-368页

作者： Chengrong YU Zehua PAN Hongying ZHANG Bin CHEN Wanbing GUAN Bin MIAO Siew Hwa CHAN zheng ZHONG Yexin ZHOU school of science Harbin Institute of TechnologyShenzhen 518055China Guangdong Provincial Key Laboratory of Deep Earth sciences and Geothermal energy Exploitation and Utilization Institute of Deep Earth Sciences and Green EnergyShenzhen UniversityShenzhen 518060China Key Laboratory of Advanced Fuel Cells and Electrolyzers technology of Zhejiang Province Ningbo Institute of Materials Technology and Engineering of the Chinese Academy of SciencesNingbo 315201China energy Research institute at NTU(ERIAN) Nanyang Technological UniversitySingapore 639798Singapore

Due to the depletion of traditional fossil fuels and the aggravation of related environmental problems,hydrogen energy is gaining more attention all over the *** oxide fuel cell(SOFC)is a promising power generation technology operating on hydrogen with a high *** further boost the power output of a single cell and thus a single stack,increasing the cell area is an effective ***,it was recently found that further increasing the effective area of an SOFC single cell with a flat-tubular structure and symmetric double-sided cathodes would result in a lower areal *** this work,a multi-physical model is built to study the effect of the effective area on the cell *** distribution of different physical fields is systematically *** of the cell performance is also pursued by systematically tuning the cell operating condition and the current collection *** improvement of 42%is revealed by modifying the inlet gas flow rates and by enhancing the current *** the future,optimization of cell geometry will be performed to improve the homogeneity of different physical fields and thus to improve the stability of the cell.

关键词： solid oxide fuel cell(SOFC) large effective area flow rate discharge performance current collection

Numerical study on the characteristics of natural supercavitation by planar symmetric wedge-shaped cavitators for rotational supercavitating evaporator

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science China(Technological sciences) 2015年第6期58卷 1072-1083页

作者： zheng zhiying LI FengChen LI Qian KULAGIN Vladimir A school of energy science and engineering Harbin Institute of Technology Department of Heat technology and Fluid Dynamics Siberian Federal University

With the application of supercavitation effect, a novel device named rotational supercavitating evaporator(RSCE) was recently designed for desalination. In order to improve the blade shape of rotational cavitator in RSCE for performance optimization and then design three-dimensional blades, numerical simulations are conducted on the supercavitating flows(with cavitation number ranging from 0.055 to 0.315) around two-dimensional planar symmetric wedge-shaped cavitators with different wedge angles varied from 10 to 180 degrees. Proper numerical method for simulating supercavitating flows around planar symmetric cavitator is established, and assessment of k-ε-v2 -f turbulence model in simulating cavitating flows is conducted. It shows that the size of computational domain would affect the simulation result. Empirical formulae for supercavity dimensions about cavitation number at different wedge angles are obtained, which are of significant importance in the subsequent design of three-dimensional blade. The characteristics of resistance at different wedge angles are discussed, which, together with the characteristics of supercavity dimensions, play important roles in the optimal design of RSCE.

关键词： rotational supercavitating evaporator desalination planar symmetric wedge-shaped cavitators CFD numerical simulation

Theoretical Exploration of Alloying Effects on Stabilities and Mechanical Properties ofγʹPhase in Novel Co–Al–Nb-Base Superalloys

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Acta Metallurgica Sinica(English Letters) 2024年第7期37卷 1238-1248页

作者： Guan-Cheng Gu Zhao-Jing Han Ze-Yu Chen Zhao-Xuan Li Sheng-Bao Xia zheng-Ning Li Hua Jin Wei-Wei Xu Xing-Jun Liu Shenzhen Research institute of Xiamen University School of Aerospace EngineeringXiamen UniversityXiamen361005China institute of Materials Genome and Big Data Harbin Institute of TechnologyShenzhen518055China

The new developedγ/γʹCo–Al–Nb-base alloys show great potentials as high-temperature ***,finding appropriate compositions to improve performance of alloys still poses a great challenge to the development of Co–Al–Nb-base *** by the lack of alloying effects on fundamental properties of criticalγʹphase,we systematically performed a theoretical investigation on the effect of alloying elements TM(TM:Ti,V,Cr,Zr,Mo,Ta,W,Re,and Ru)on phase stabilities and mechanical properties of L1_(2)-typeγʹ(Co,Ni)_(3)(Al,Nb).By analyzing the stability ofγʹphase with respect to its competitive B2 and D0_(19) phases,the results shown that Ti,V,and Cr enhance the L1_(2) stability and widen the L1_(2)–D0_(19) energy barrier,in which V yields the maximum *** analysis of electronic structure indicated that the alternation of valence electrons at fermi level would be the atomic origin for doping TM inγʹ*** calculated results of mechanical properties shown that V and Cr are expected to be optimal dopant for enhancing the strength and the ductility ofγʹ*** addition of Ta is also beneficial for enhancing the strength at the slight expense of ductility ofγʹ*** drawing the mechanical maps,the preferred composition range for the phases with desired properties is roughly demarcated in theory for the multi-addition of V/Cr and V/Ta inγʹ*** findings would be useful for optimizing the performance of novelγ/γʹCo–Al–Nb-base superalloys.

关键词： Co-Al-Nb-base superalloys γ/γʹdual-phase Phase stability Mechanical properties First-principle methods