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Journal of Hydrodynamics 2024年第2期36卷 219-231页

作者： Chen Geng Zhao-hui Qian Ke-xin Zheng Wei-xian. Ye xian.wu Luo State Key Laboratory of Hydroscience cand Engineering Deparment of Energy and Power EngineeringTsinghua UniversityBeijing 100084China Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China

In the present paper,the unsteady cavitating turbulent flow over the twisted NACA66 hydrofoil is investigated based on an modified shear stress transfer k-ωpartially averaged Navier-Stokes(MSST PANS)model,i.e.,new MSST PANS(NMSST PANS)model,where the production term of kinetic energy in the turbulence model is modified with *** with the experimental data,cavitation evolution and its characteristic frequency are satisfactorily predicted by the proposed NMSST PANS *** is revealed that the interaction among the main flow,the reentrant jets,and sheet cavitation causes the formation of the primary shedding cavity near the mid-span and the secondary shedding cavity at each side of the twisted hydrofoil,and further induces the remarkable pressure gradient around shedding *** with the development of the primary and the secondary shedding cavities,the great pressure gradient associated with large cavity volume variation promotes the vortical flow generation and the spatial deformation of vortex structure during cavitation evolution,and results in the primary and the secondary U-type ***,dynamic mode decomposition(DMD)analysis is utilized to confirm the interaction among the main flow,the main reentrant jet and two side reentrant jets,and *** results indicate that the proposed NMSST PANS model is suitable to simulate the complicated cavitating turbulent flow for various engineering applications.

关键词： Cavitating turbulent flow partially averaged Navier-Stokes(PANS)model hydrofoil numerical simulation

Elastohydrodynamic Lubrication Interface Stiffness and Damping Considering Asperity Lateral Contact

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Acta Mechanica Solida Sinica 2024年第1期37卷 109-123页

作者： Zhiqiang Gao Yu Zhang xian.Wei Yanfang Zhu Lixia Peng Weiping Fu Wen Wang School of Mechanical and Precision Instrument Engineering Xi'an University of TechnologyXi'an 710048China School of Intelligent Manufacturing Panzhihua UniversityPanzhihua 617000China Material Corrosion and Protection Key Laboratory of Sichuan Province Sichuan University of Light Chemical TechnologyYibin 644002China School of Mechanical Engineering Anyang Institute of TechnologyAnyang 455099China

Elastohydrodynamic lubrication(EHL)point contact occurs between two rough surfaces at the mesoscopic level,while the interaction of rough surfaces involves contact between asperities at the microscale *** most cases,the contact between asperities within an interface takes the form of lateral contact rather than peak *** devoid of contact asperities are filled with lubricating ***,conventional models often oversimplify lateral contact forms as interactions between asperities and a smooth,rigid *** simplifications fail to accurately represent the true contact conditions and can lead to inaccuracies in the analysis of EHL’s contact *** address this issue,we have developed a novel EHL interface model comprising two rough *** model allows us to explore the influence of asperity height,contact angle,and contact azimuth angle on EHL interface performance.

关键词： EHL interface Asperity lateral contact Contact stiffness Damping

Experimental Study on Mixed-Mode(Ⅰ–Ⅱ)Fracture Toughness of Freshwater Ice

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Acta Mechanica Solida Sinica 2024年第2期37卷 252-264页

作者： Yaozhong Xu Mao Zhou xian.Yi Wen Hua Jiuzhou Huang Wenyu Zhang Shiming Dong Key Laboratory of Deep Underground Science and Engineering Ministry of EducationCollege of Architecture and EnvironmentSichuan UniversityChengdu610065China Failure Mechanics and Engineering Disaster Prevention Key Laboratory of Sichuan Province Sichuan UniversityChengdu610065China China Aerodynamics Research and Development Center/Low Speed Aerodynamics Research Institute Mianyang621000China College of Mechanical and Electrical Engineering Xichang UniversityXichang615000China

In recent years,the issue of aircraft icing has gained widespread *** breaking and detachment of dynamic ice can pose a threat to flight ***,the shedding and fracture mechanisms of dynamic ice are unclear and cannot meet the engineering needs of ice-shedding hazard ***,studying the fracture toughness of ice bodies has extremely important practical *** address this issue,this article uses a centrally cracked Brazilian disk(CCBD)specimen to measure the pure modeⅠtoughness and pure modeⅡfracture toughness of freshwater ice at different loading *** mixed-mode(Ⅰ–Ⅱ)fracture characteristics of ice are discussed,and the experimental results are compared and analyzed with the theoretical values of the generalized maximum tangential stress(GMTS)criterion considering the influence of *** results indicated that as the loading rate increases,the pure modeⅠtoughness and pure modeⅡfracture toughness of freshwater ice decrease,and the fracture toughness of freshwater ice is more sensitive to the loading rate.Ⅰn terms of fracture criteria,the theoretical value of the ratio of pure modeⅡfracture toughness to pure modeⅠfracture toughness based on the GMTS criterion is in good agreement with the experimental value,while the theoretical value based on the maximum tangential stress(MTS)criterion deviates significantly from the experimental value,indicating that the GMTS criterion considering the influence of T-stress can better predict the experimental results.

关键词： Freshwater ice Fracture criteria Centrally cracked Brazilian disk(CCBD) Mixed-mode(Ⅰ-Ⅱ) Loading rate

Coordination environments build up and tune a superior synergistic “genome” toward novel trifunctional (TM-N_(x)O_(4−x))@g- C_(16)N_(3)-H_(3): High-throughput inspection of ultra-high activity for water splitting and oxygen reduction reactions

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Nano Research 2024年第4期17卷 2337-2351页

作者： Chunyao Fang xian.Wang Qiang Zhang Xihang Zhang Chenglong Shi Jingcheng Xu Mengyu Yang Department of Physics University of Shanghai for Science and TechnologyShanghai 200093China School of Materials and Chemistry University of Shanghai for Science and TechnologyShanghai 200093China

Emerging as a prominent area of focus in energy conversion and storage technologies,the development of highly active metal-based single-atom catalysts(SACs)holds great signiﬁcance in searching alternatives to replace precious metals toward the efficient,stable,and low-cost hydrogen evolution reaction(HER),as well as the oxygen evolution reaction(OER)and the oxygen reduction reaction(ORR).Combining the tremendous tunability of ligand and coordination environment with rich metal-based electrocatalysts can create breakthrough opportunities for achieving both high stability and ***,we propose a novel and stable holey graphene-like carbon nitride monolayer g-C_(16)N5(N_(4)@g-C_(16)N_(3))stoichiometries interestingly behaving as a natural substrate for constructing SACs((TM-N_(4))@g-C_(16)N_(3)),whose evenly distributed holes map rich and uniform nitrogen coordination positions with electron-rich lone pairs for anchoring transition metal(TM)***,we employed density functional theory(DFT)calculations to systematically investigate the electrocatalytic activity of(TM-N_(4))@g-C_(16)N_(3) toward HER/OER/ORR,meanwhile considering the synergistic modulation of H-loading and O-coordination((TM-N_(x)O_(4-x))@g-C_(16)N_(3)^(-)H_(3),x=0–4).Together a“four-step procedure”screening mechanism with the first-principles high-throughput calculations,we find that(Rh-N_(4))and(Ir-N_(2)O_(2)-II)distributed on g-C_(16)N_(3)^(-)H_(3) can modulate the adsorption strength of the adsorbates,thus achieving the best HER/OER/ORR performance among 216 candidates,and the lowest overpotential of 0.098/0.3/0.46 V and 0.06/0.48/0.45 V,***,the d-band center,crystal orbital Hamilton population(COHP),and molecular orbitals are used to reveal the OER/ORR activity ***,the Rh/Ir-d orbital is dramatically hybridized with the O-p orbital of the oxygenated adsorbates,so that the lone-electrons incipiently locate at the antibonding orbital pair up and popula

关键词： single atom catalysts loading and coordination hydrogen evolution reaction oxygen evolution reaction oxygen reduction reaction

Particle distributions in Lamb wave based acoustofluidics

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Nanotechnology and Precision Engineering 2024年第2期7卷 60-68页

作者： Chuanchao Zhang xian.Chen Wei Wei Xuejiao Chen Quanning Li Xuexin Duan Key Laboratory of Precision Measuring Technology and Instruments College of Precision Instrument and Optoelectronics EngineeringTianjin UniversityTianjin300072China

Acoustic streaming enabled by a Lamb wave resonator(LWR)is efficient for particle trapping and enrichment in microfluidic ***,because Lamb waves combine the features of bulk acoustic waves and surface acoustic waves,the resulting acoustic streaming in the LWR occurs in multiple planes,and the particle flow behavior in this acoustofluidic system is largely *** here are numerical simulations and laboratory experiments conducted to investigate the boundary conditions for particle motion inside a microvortex induced by an *** dynamic capture,the particles’trajectories become orbital paths within an acoustic *** suspended particles encounter two distinct acoustic phenomena,i.e.,the drag force resulting from acoustic streaming and the acoustic radiation force,which exert forces in various directions on the *** the acoustic radiation force and the fluid drag force are dominant for large and small particles in a mixed solution,respectively,the large particles reside within the vortex while the small particles remain at its ***,when the acoustic radiation force is dominant for both types of particles,the distribution pattern is reversed.

关键词： Acoustofluidics Lamb wave resonator Particle manipulation Microvortex

A 27 GHz,simple 2-bit 1×8 phased array

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Journal of Electronic Science and Technology 2024年第3期22卷 26-34页

作者： Jun-xian.Liu Yun-Ying Man Hao Yang Peng Yang School of Electronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu611731China

This study demonstrates a simple 2-bit phased array operating at 27 GHz that supports one-dimensional beam scanning with left-handed circular polarization(LHCP).The antenna is constructed using a compact four-layer printed circuit board(PCB)structure,consisting of a 90°phase shifter layer with microstrip structures,a ground(GND)layer,a direct current(DC)control layer,and a circularly polarized annular radiation patch layer with 1-bit phase *** on the proposed unit structure,a 1×8 array with half-wavelength inter-element spacing was designed and *** results show that the array achieves a peak gain of 10.23 dBi and is capable of beam scanning within±50°.

关键词： 27 GHz 2-bit P-i-n diodes Phased array Reconfigurable antennas

Flexural behavior of textile reinforced mortar-autoclaved lightweight aerated concrete composite panels

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Frontiers of Structural and Civil Engineering 2024年第5期18卷 776-787页

作者： Liying GUO Mingke DENG Wei ZHANG Tong LI Yangxi ZHANG Mengyu CAO xian.HU Department of Civil Engineering Xi’an University of Architecture and TechnologyXi’an 710055China Key Lab of Structural Engineering and Earthquake Resistance Ministry of Education(XAUAT)Xi’an 710055China Scene engineering design institute Xi’an 710016China Dahua Group Shang hai 200062China

To improve the deficiencies of prefabricated autoclaved lightweight aerated concrete(ALC)panel such as susceptibility to cracking and low load-bearing capacity,a textile-reinforced mortar-autoclaved lightweight aerated concrete(TRM-ALC)composite panel was developed in this *** group of reference ALC panels and five groups of TRM-ALC panels were fabricated and subjected to four-point flexural *** was applied on the tensile side of the ALC panels to create *** variable parameters were the plies of textile(one or two),type of textile(basalt or carbon),and whether the matrix(without textile)was applied on the compression side of *** results showed that a bonding only 8-mm-thick TRM layer on the surface of the ALC panel could increase the cracking load by 180%−520%.The flexural capacity of the TRM-ALC panel increased as the number of textile layers *** reinforcement of the matrix on the compressive side could further enhance the stiffness and ultimate loadbearing capacity of the TRM-ALC *** panels with basalt textile failed in flexural mode,with the rupture of fabric *** with carbon textile failed in shear mode due to the ultra-high tensile strength of *** addition,analytical models related to the different failure modes were presented to estimate the ultimate load-carrying capacity of the TRM-ALC panels.

关键词： prefabricated autoclaved lightweight aerated concrete panel textile-reinforced mortar cracking load flexural capacity stiffness

Synergistic Effects of Carbon Nanotube(CNT)and Reduced Graphene Oxide(RGO)on Mechanical and Thermal Properties of ZK61 Alloy

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Acta Metallurgica Sinica(English Letters) 2024年第3期37卷 577-585页

作者： Fanjing Meng Wenbo Du Ning Ding Jian Sun xian.Du Ke Liu Shubo Li College of Materials Science and Engineering Faculty of Materials and ManufacturingBeijing University of TechnologyBeijing 100124China

The hybrid of carbon nanotube(CNT)and reduced graphene oxide(RGO)reinforced ZK61 composite was fabricated by a hot extrusion *** with the raw ZK61 alloy and single-reinforced composites,the hybrid-reinforced by RGO+CNT complex exhibited significant enhancements both in mechanical and thermal *** adjusting the proportion of RGO and CNT in ZK61 alloy,the obtained optimum ZK61/(0.06 wt%RGO+0.54 wt%CNT)composite exhibited increase of 25.4%in yield strength,26.5%in ultimate tensile strength,104%in failure strain and 30.4%in thermal conductivity,respectively,in comparison with ZK61 *** superior properties of the nano-hybrid composite are attributed to the synergetic effects of RGO and CNT,leading to a uniform dispersion and integrated structure as well as the enhanced interfacial bonding with *** strengthening ability of RGO and CNT was calculated to quantify their individual contribution to the improvement in mechanical and thermal properties of the ZK61 matrix *** RGO+CNT hybrids provide a promising way to develop Mg matrix composites with impressive performances.

关键词： Mg matrix composite Carbon nanotube Reduced graphene oxide Mechanical performance Thermal conductivity

First-principles study on the heterogeneous formation of environmentally persistent free radicals(EPFRs)overα-Fe2O3(0001)surface:Effect of oxygen vacancy

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Journal of Environmental Sciences 2024年第8期142卷 279-289页

作者： Wenxiao Pan Shuming He Qiao Xue xian.Liu Jianjie Fu Kang Xiao Aiqian Zhang State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China School of Environment Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310012China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China Beijing Yanshan Earth Critical Zone National Research Station University of Chinese Academy of SciencesBeijing 101408China

Metal oxides with oxygen vacancies have a significant impact on catalytic activity for the transformation of organic pollutants in waste-to-energy(WtE)incineration *** study aims to investigate the influence of hematite surface oxygen point defects on the formation of environmentally persistent free radicals(EPFRs)from phenolic compounds based on the first-principles *** oxygen-deficient conditions were considered:oxygen vacancies at the top surface and on the *** simulations indicate that the adsorption strength of phenol on theα-Fe_(2)O_(3)(0001)surface is enhanced by the presence of oxygen ***,the presence of oxygen vacancies has a negative impact on the dissociation of the phenol molecule,particularly for the surface with a defective point at the top ***-kinetic parameters were established over a temperature range of300-1000 K,and lower reaction rate constants were observed for the scission of phenolic O-H bonds over the oxygen-deficient surfaces compared to the pristine *** negative effects caused by the oxygen-deficient conditions could be attributed to the local reduction of FeⅢto FeⅡ,which lower the oxidizing ability of surface reaction *** findings of this study provide us a promising approach to regulate the formation of EPFRs.

关键词： EPFR formation Phenol dissociation Oxygen-vacancy impact Hematite surface First-principles calculation

Efficacy and safety of minimally invasive laparoscopic surgery under general anesthesia for ovarian cancer

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World Journal of Clinical Cases 2024年第9期12卷 1569-1577页

作者： xian.Qin Chen Chen Yang Liu xian.Hong Hua Jia-Yi Li Meng-Jie Liang Fang Wu Department of Anesthesiology The First People's Hospital of Jiangxia DistrictWuhan 430200Hubei ProvinceChina Department of Obstetrics and Gynecology The First People's Hospital of Jiangxia DistrictWuhan 430200Hubei ProvinceChina

BACKGROUND Ovarian cancer is one of the most common malignant tumors in female reproductive system in the world,and the choice of its treatment is very important for the survival rate and prognosis of *** open surgery is the main treatment for ovarian cancer,but it has the disadvantages of big trauma and slow *** the continuous development of minimally invasive technology,minimally invasive laparoscopic surgery under general anesthesia has been gradually applied to the treatment of ovarian cancer because of its advantages of less trauma and quick ***,the efficacy and safety of minimally invasive laparoscopic surgery under general anesthesia in the treatment of ovarian cancer are still *** To explore the efficacy and safety of general anesthesia minimally invasive surgery in the treatment of ovarian *** The clinical data of 90 patients with early ovarian cancer in our hospital were analyzed *** to the different surgical treatment methods,patients were divided into study group and control group(45 cases in each group).The study group received minimally invasive laparoscopic surgery under general anesthesia for ovarian cancer,while the control group received traditional open surgery for ovarian *** European Organization for Research and Treatment of Cancer Quality of Life Questionnaire(EORTC QLQ-C30),clinical efficacy and safety of the two groups were *** The intraoperative blood loss,length of hospital stay,postoperative gas evacuation time,and postoperative EORTC QLQ-C30 score of the study group were significantly better than those of the control group(P<0.05).The incidence of postoperative complications in the study group was significantly lower than in the control group(P<0.05).The two groups had no significant differences in the preoperative adrenocorticotropic hormone(ACTH),androstenedione(AD),cortisol(Cor),cluster of differentiation 3 positive(CD3+),and clu

关键词： Early-stage ovarian cancer Efficacy Minimally invasive Laparoscopy Safety Surgery