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Unsteady aerodynamic noise prediction of contra-rotating open rotor using meshless method

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Chinese Journal of Aeronautics 2024年第8期37卷 144-165页

作者： Zhiliang hong Meng su Haitao ZHANG Zerui XU Lin DU Lingfeng CHEN College of Safety Science and Engineering Civil Aviation University of ChinaTianjin 300300China Civil Aviation Administration of China Beijing 100710China Research Institute of Aero-Engine Beihang UniversityBeijing 100191China

The Contra-Rotating Open Rotor(CROR)design confronts significant noise challenges despite being one of the possible options for future green *** efficiently estimate the noise emitted from a CROR,a three-dimensional unsteady prediction model based on the meshless method is *** unsteady wake flow and the aerodynamic load fluctuations on the blade are solved through the viscous vortex particle method,the blade element momentum theory and vortex lattice ***,the acoustic field is obtained through the Farassat’s formulation *** of this method is conducted on a CROR,and a mesh-based method,e.g.,Nonlinear Harmonic(NLH)method,is also employed for *** is found that the presented method is three times faster than NLH method while maintaining a comparable precision.A thorough parametric analysis is also carried out to illustrate the effects of rotational speed,rotor-rotor spacing and rear rotor diameter on the noise *** rotor speed is found to be the most influencing factor,and by optimizing the speed difference between the front and rear rotors,a notable noise reduction can be *** current findings not only contribute to a deeper comprehension of the CROR’s aeroacoustic properties but also offer an effective tool for engineering applications.

关键词： Contra-Rotating Open Rotor(CROR) Aerodynamic noise Blade element momentum theory Viscosity vortex particle method Farassat’s formulation 1A

Boring holes in Au nanoplates by active surface etching

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Nano Research 2024年第9期17卷 8610-8617页

作者： Haiyang Hu Yuntao Wang Qian Wang Xudong Peng An su hong Wang hongyu Chen Institute of Advanced Synthesis(IAS)and School of Chemistry and Molecular Engineering Jiangsu National Synergetic Innovation Centre for Advanced MaterialsNanjing Tech UniversityNanjing 211816China Department of Environmental Science and Engineering University of Science and Technology of ChinaHefei 230026China Department of Chemistry School of Science and Key Laboratory for Quantum Materials of Zhejiang ProvinceResearch Center for Industries of the FutureWestlake UniversityHangzhou 310030China Institute of Natural Sciences Westlake Institute for Advanced StudyHangzhou 310024China

In contrast to the conventional etching that makes nanoparticles rounder and our previous sharpening etching mode that causes serrated edges,here,we developed a new boring etching mode that targets the faces of Au nanoplates to make *** critical factors are the pre-incubation step with the ligand 2-mercapto-5-benzimidazolecarboxylic acid(MBIA)and the subsequent removal of excess ligands in the ***,etching is focused onto the few sites with initial loss of ligands,which cannot be quickly *** choice of ligand MBIA is also of importance,as it carries negative charge and repels each *** inability of forming a dense layer probably plays a critical role in the site-selectivity for faces,because ligands at the higher curvature edges and corners are expected to have less *** etching results from the comproportionation reaction between Au3+and Au0 in the nanoplates,where Br-coordination to Au and the extra stabilization from cetyltrimethylammonium bromide(CTAB)are *** believe that the ability of boring holes is an important tool for future synthetic designs.

关键词： Au nanoplates active surface etching boring etching mode cetyltrimethylammonium bromide(CTAB)passivation holes

Optimization of fertilizer performances in long-term garlic cropping soils

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Pedosphere 2024年第3期34卷 577-589页

作者： Tianqi WEI hongmei ZHOU Huayang hong Yanyun REN Qin LIU Yanhua su Institute of Soil Science Chinese Academy of SciencesNanjing 210008(China) University of Chinese Academy of Sciences Beijing 100049(China) University of Chinese Academy of Sciences NanjingNanjing 211135(China) Jining Academy of Agricultural Sciences Jining 272100(China) College of Forestry Nanjing Forestry UniversityNanjing 210037(China)

Continuous cropping is a common pattern of modern agriculture that takes regional advantages for crop yield *** the progress of mono-cropping continuously supported by intensive fertilizer inputs,such a cropping pattern often undergoes serious problems with low fertilizer use efficiencies and unsustainable crop *** this study,we dealt with a>25-year continuous garlic cropping system as an example for a problem-solving *** garlic cropping soils underwent problems characterized by loss of soil organic matter,dramatic retention of NH_(4)^(+)-N,and excess accumulation of phosphate and potash *** hydroponic simulations,we revealed that the presence of NH_(4)^(+)-N inhibited the root uptake of NO_(3)^(-)-N and K by 68% and 88%,*** the traditionally emphasized importance of K,we observed the negative effect of high K on the growth of garlic *** field experiments demonstrated that P and K applications can be reduced by 60% and 50%,respectively,without loss of *** thus developed a high-performance fertilization strategy by integrating a recomposed NPK fertilizer formulation to reduce unnecessary P and K inputs,a supplementary application of long-lasting C of woody peat to compensate for the soil C loss,and a foliar K approach to strengthen the stomatal function improvement with *** strategy allowed a 15% increase of garlic yield and a seasonal soil C profit of ca.1.8 Mg ha^(-1)even at ca.30% lower fertilizer *** study would be helpful in managing garlic fertilization and developing compound fertilizers,with broader significance for other long-term cropping soils.

关键词： fertilization strategy fertilizer input field validation hydroponic simulation optimized fertilization soil nutrient balance yield profit

Polar solvent induced in-situ self-assembly and oxygen vacancies on Bi_(2)MoO_(6)for enhanced photocatalytic degradation of tetracycline

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Nano Research 2024年第6期17卷 4951-4960页

作者： Fangyan Liu Dongyue su Weizhen Liu Baiquan Liu Chuan Liu hong Wang Mengye Wang State Key Laboratory of Optoelectronic Materials and Technologies Guangdong Province Key Laboratory of Display Material and TechnologySchool of Electronics and Information TechnologySun Yat-Sen UniversityGuangzhou 510275China School of Materials Sun Yat-Sen UniversityShenzhen 518107China School of Environment and Energy Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and RecyclingSouth China University of TechnologyGuangzhou 510006China

It has been proved to be an effective route to efficiently ameliorate photocatalytic performance of catalysts via designing three-dimensional(3D)hierarchical nanostructures and constructing oxygen vacancies(VOs).However,controlling the self-assembly of organization into 3D hierarchical nanostructures while introducing VOs in photocatalysts remains a ***,we reported an ethylene glycol(EG)mediated approach to craft 3D hydrangea-structure Bi_(2)MoO_(6)with VOs for efficient photocatalytic degradation of *** manipulating the EG concentration during the fabrication process,the influence of EG concentration on the Bi_(2)MoO_(6)structure was systematically *** could promote the self-assembly of Bi_(2)MoO_(6)nanosheets to form a 3D hierarchical *** with 2D nanoplates,3D hierarchical architecture enhanced the surface area and the amount of active sites of Bi_(2)MoO_(6).In addition,the reduction effect of EG on metallic oxide enabled the generation of VOs in Bi_(2)MoO_(6).The VOs adjusted the electronic structure of Bi_(2)MoO_(6),which not only enhanced the light harvesting,but also facilitated the simultaneous utilization of photo-induced electrons and holes to form reactive oxygen species(·O2−and·OH)for the efficient tetracycline decomposition.3D Bi_(2)MoO_(6)hydrangea with VOs achieved a 79.4%removal efficiency of tetracycline after 75 *** work provides a simple yet robust EG-mediated strategy,which not only promotes the self-assembly of nano-catalysts into 3D hierarchical architectures,but also crafts tunable VOs for highly efficient photocatalysis.

关键词： three-dimensional(3D)hierarchical nanostructures tunable oxygen vacancies ethylene glycol(EG)-mediated strategy bismuth molybdate photocatalytic degradation tetracycline

Assessment of Dependent Performance Shaping Factors in SPAR-H Based on Pearson Correlation Coefficient

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Computer Modeling in Engineering & Sciences 2024年第2期138卷 1813-1826页

作者： Xiaoyan su Shuwen Shang Zhihui Xu hong Qian Xiaolei Pan School of Automation Engineering Shanghai University of Electric PowerShanghai 200090China State Key Laboratory of Nuclear Power Safety Monitoring Technology and Equipment Shenzhen518172China

With the improvement of equipment reliability,human factors have become the most uncertain part in the *** standardized Plant Analysis of Risk-Human Reliability Analysis(SPAR-H)method is a reliable method in the field of human reliability analysis(HRA)to evaluate human reliability and assess risk in large complex ***,the classical SPAR-H method does not consider the dependencies among performance shaping factors(PSFs),whichmay cause overestimation or underestimation of the risk of the actual *** address this issue,this paper proposes a new method to deal with the dependencies among PSFs in SPAR-H based on the Pearson correlation ***,the dependence between every two PSFs is measured by the Pearson correlation ***,the weights of the PSFs are obtained by considering the total dependence ***,PSFs’multipliers are modified based on the weights of corresponding PSFs,and then used in the calculating of human error probability(HEP).A case study is used to illustrate the procedure and effectiveness of the proposed method.

关键词： Reliability evaluation human reliability analysis SPAR-H performance shaping factors dependence pearson correlation analysis

Single-cluster electronics using metallic clusters:Fabrications,regulations,and applications

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Nano Research 2024年第1期17卷 65-78页

作者： Caiyun Wei Wei Xu Shurui Ji Ruiyun Huang Junyang Liu Wenqiu su Jie Bai Jiale Huang Wenjing hong State Key Laboratory of Physical Chemistry of Solid surfaces National Engineering Research Centre of Chemicals for Electronic ManufacturingCollege of Chemistry and Chemical Engineering&Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM)Xiamen UniversityXiamen 361005China

Metallic clusters,ranging from 1 to 2 nm in size,have emerged as promising candidates for creating nanoelectronic devices at the single-cluster *** the intermediate quantum properties between metals and semiconductors,these metallic clusters offer an alternative pathway to silicon-based electronics and organic molecules for miniaturized electronics with dimensions below 5 *** progress has been made in studies of single-cluster electronic ***,a clear guide for selecting,synthesizing,and fabricating functional single-cluster electronic devices is still *** review article provides a comprehensive overview of single-cluster electronic devices,including the mechanisms of electron transport,the fabrication of devices,and the regulations of electron transport ***,we discuss the challenges and future directions for single-cluster electronic devices and their potential applications.

关键词： single-cluster junctions electronic properties electron transport metallic clusters structure regulation

Analysis of mechanical strengths of extreme line casing joint considering geometric, material, and contact nonlinearities

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Petroleum Science 2024年第3期21卷 1992-2004页

作者： Ji-Yun Zhang Chi Peng Jian-hong Fu Quan Cao Yu su Jian-Yun Pang Zi-Qiang Yu Petroleum Engineering School Southwest Petroleum UniversityChengdu610500SichuanChina Engineering Technology Research Institute of CNPC Southwest Oil and Gas Field Company Chengdu610017SichuanChina

To address the challenges associated with difficult casing running,limited annular space,and poor cementing quality in the completion of ultra-deep wells,the extreme line casing offers an effective solution over conventional ***,due to its smaller size,the joint strength of extreme line casing is reduced,which may cause failure when running in the *** address this issue,this study focuses on the CST-ZTΦ139.7 mm×7.72 mm extreme line casing and employs the elastic-plastic mechanics to establish a comprehensive analysis of the casing joint,taking into account the influence of geometric and material nonlinearities.A finite element model is developed to analyze the forces and deformations of the extreme line casing joint under axial tension and external collapse *** model investigates the stress distribution of each thread tooth subjected to various tensile forces and external ***,the tensile strength and crushing strength of the extreme line casing joint are determined through both analytical and experimental *** findings reveal that,under axial tensile load,the bearing surface of each thread tooth experiences uneven stress,with relatively high equivalent stress at the root of each thread *** end thread teeth are valuable spots for *** is observed that the critical fracture axial load of thread decreases linearly with the increase of thread tooth *** external pressure,the circumferential stress is highest at the small end of the external thread,leading to yield *** tensile strength of the joint obtained from the finite element model exhibits a relative error of less than 7%compared to the analytical and experimental values,proving the reliability of the finite element *** tensile strength of the joint is 3091.9 k ***,in terms of anti-collapse capability,the joints demonstrate higher resistance to collapse compared to the casing body,which is consistent with the test resul

关键词： Extreme line casing Elastic-plastic mechanics Finite element analysis Tensile strength Collapse strength

Room-temperature Self-healing and Recyclable PDMS Elastomers with superior Mechanical Properties for Triboelectric Nanogenerators

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Chinese Journal of Polymer Science 2024年第10期42卷 1566-1577,I0014页

作者： Shu-Juan Wang Lu Wang hong-Zhe su Zhi-Cheng Wu Qiao-Gen Zhang Wei Fan Xin-Li Jing School of Chemistry Joint Innovation Center of Thermal Protection MaterialsXi’an Jiaotong UniversityXi’an710049China School of Electrical Engineering Xi’an Jiaotong UniversityXi’an710049China School of Textile Science and Engineering Xi’an Polytechnic UniversityXi’an710048China

Polydimethylsiloxane(PDMS)is an electron-withdrawing material that is widely used in triboelectric nanogenerators(TENGs).However,PDMS has poor mechanical properties after curing and is easily damaged when subjected to long-term ***,the long-term stable operation of TENGs under mechanical deformation cannot be *** this work,multiple hydrogen bonds and aromatic disulfide bonds were introduced into PDMS *** elastomers exhibited high toughness(a tensile strength of 1.91 MPa and an elongation at break of 340%),good recyclability,and room-temperature self-healing properties(healing efficiency of 96.4%in 24 h).Recyclable sandwich-like triboelectric nanogenerators with excellent electrical output performance(13.5 V)and room-temperature self-healing performance(24 h,98%recovery of self-generating performance)were prepared by utilizing the hydrogen bonding between the PDMS elastomer and *** work reported herein offers theoretical guidance and a compelling strategy for developing high-performance TENG negative friction layers.

关键词： Polydimethylsiloxane Aromatic disulfide bonds Hydrogen bonds Room temperature self-healing Triboelectric nanogenerator

Numerical and Experimental Analysis of the Aerodynamic Torque for Axle-Mounted Train Brake Discs

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Fluid Dynamics & Materials Processing 2024年第8期20卷 1867-1882页

作者： Nan Liu Chen hong Xinchao su Xing Jin Chen Jiang Yuqi Shi Bingkun Wang Brake System Laboratory CRCC(Qingdao)Vehicle Inspection Station Co.Ltd.Qingdao266031China Brake System Laboratory CRRC Qingdao Sifang Rolling Stock Research Institute Co.Ltd.Qingdao266031China The State Key Laboratory of Heavy-Duty and Express High-Power Electric Locomotive Central South UniversityChangsha410075China Key Laboratory of Traffic Safety on Track of Ministry of Education School of Traffic&Transportation EngineeringCentral South UniversityChangsha410075China National&Local Joint Engineering Research Center of Safety Technology for Rail Vehicle Changsha410075China

As the velocity of a train increases,the corresponding air pumping power consumption of the brake discs increases *** the present experimental study,a standard axle-mounted brake disc with circumferential pillars was analyzed using a 1:1 scale model and a test rig in a wind *** particular,three upstream velocities were selected on the basis of earlier investigations of trains operating at 160,250,and 400 km/h,***,3D steady computational fluid dynamics(CFD)simulations of the flow field were conducted to compare with the wind tunnel test *** results for a 3-car train at 180 km/h demonstrated:(1)good agreement between the air resistance torques obtained from the wind tunnel tests and the related numerical results,with differences ranging from 0.95%to 5.88%;(2)discrepancies ranging from 3.2 to 3.8 N·m;(3)cooling ribs contributing more than 60%of the air resistance torque;(4)the fast rotation of brake discs causing a significantly different flow field near the bogie area,resulting in 25 times more air pumping power loss than that obtained in the stationary brake-disc case.

关键词： Axle-mounted train brake disc aerodynamic torque wind tunnel test numerical simulation