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High Voltage 2024年第5期9卷 1136-1148页

作者： Yongming xu ziyi xu Congrui Ren Yaodong Wang School of Electrical and Information Engineering Changzhou Institute of TechnologyChangzhouChina School of Electrical and Electronic Engineering Harbin University of Science and TechnologyHarbinChina Department of Engineering Durham UniversityDurhamUK

Due to the complex structure and large size of large-capacity oil-immersed power transformers,it is difficult to predict the winding temperature distribution directly by numerical analysis.A 180 MVA,220 kV oil-immersed self-cooling power transformer is used as the research *** authors decouple the internal fluid domain of the power transformer into four regions:high voltage windings,medium voltage windings,low voltage windings,and radiators through fluid networks and establish the 3D fluidtemperature field numerical analysis model of the four regions,*** results of the fluid network model are used as the inlet boundary conditions for the 3D fluidtemperature numerical analysis *** turn,the fluid resistance of the fluid network model is corrected according to the results of the 3D fluid-temperature field numerical analysis *** prediction of the temperature distribution of windings is realised by the coupling calculation between the fluid network model and the 3D fluid-temperature field numerical analysis *** on this,the effect of the loading method of the heat source is also investigated using the proposed *** hotspot temperatures of the high-voltage,medium-voltage,and low-voltage windings are 89.43,86.33,and 80.96°C,***,an experimental platform is built to verify the *** maximum relative error between calculated and measured values is 4.42%,which meets the engineering accuracy requirement.

关键词： winding network distribution

Performance analysis and flow mechanism of channel wing considering propeller slipstream

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Chinese Journal of Aeronautics 2023年第11期36卷 165-184页

作者： Xiaoxuan MENG ziyi xu Min CHANG Junqiang BAI School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China Unmanned System Research Institute Northwestern Polytechnical UniversityXi’an 710072China Shenzhen Research Institude of Northwestern Polytechnical University Shenzhen 518057China

The development of the Urban Air Mobility concept has proposed stringent requirements for the fixed-wing vehicle’s Short/Vertical Take-Off and Landing(S/VTOL)*** its lift-enhancing impact,the channel wing,can improve aircraft low-speed performance and Short Take-Off and Landing(STOL)*** is critical for the performance analysis and flow mechanism study of a channel wing that considers the influence of propeller slipstream to guide the design of S/VTOL *** law and mechanism for the effect of the enclosing angle of the arc wing,the phase angle of the propeller,the tip clearance,the rotational speed and the chordwise position of the propeller on the channel wing are explored utilizing the quasi-steady multi reference frame method.A channel wing with a larger enclosing angle has a better ability to enhance lift and reduce drag using propeller *** effect of propeller phase angle on channel wing aerodynamic forces is periodic and *** propeller rotational speed is helpful to enhance lift and resist flow separation for channel *** can reduce drag for tractor configuration but increase drag for pusher ***,the nose-down pitching moment of a channel wing will grow dramatically,making longitudinal trimming in aircraft layout design challenging.

关键词： Channel wing Computational fluid dynamics Flow interactions Mechanisms Slipstream effect

Aerodynamic Performance of Three Flapping Wings with Unequal Spacing in Tandem Formation

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Journal of Bionic Engineering 2024年第4期21卷 1662-1676页

作者： Min Chang ziyi xu Zengshuang Chen Li Li xueguang Meng Unmanned System Research Institute National Key Laboratory of Unmanned Aerial Vehicle TechnologyNorthwestern Polytechnical UniversityXi’an710072People’s Republic of China State Key Laboratory for Strength and Vibration of Mechanical Structures School of Aerospace EngineeringXi’an Jiaotong UniversityXi’an710049People’s Republic of China Xi’an Aeronautics Computing Technique Research Institute Aviation Industry Corporation of ChinaXi’an710076People’s Republic of China

To better understand the aerodynamic reasons for highly organized movements of flying organisms,the three-flapping wing system in tandem formation was studied numerically in this *** from previous relevant studies on the multiple flapping wings that are equally spaced,this study emphasizes the impact of unequal spacing between individuals on the aerodynamics of each individual wing as well as the whole *** is found that swapping the distance between the first and second wing with the distance between the second wing and the rearmost wing does not affect the overall aerodynamic performance,but significantly changes the distribution of aerodynamic benefits across each *** the whole flapping cycle,three effects are at *** narrow channel effect and the downwash effect can promote and weaken the wing lift,respectively,while the wake capture effect can boost the *** also shows that these effects could be manipulated by changing the spacing between adjacent *** findings provide a novel way for flow control in tandem formation flight and are also inspiring for designing the formation flight of bionic aircraft.

关键词： Three flapping wings Unequal spacing Aerodynamic performance Tandem formation

Strengthening poly(2-hydroxyethyl methacrylate) hydrogels using biochars and hydrophobic aggregations

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International Journal of Smart and Nano Materials 2022年第4期13卷 561-574页

作者： Ping Zhang ziyi xu Zhiying Wu Ping xu Canhui Yang Shenzhen Key Laboratory of Soft Mechanics&Smart Manufacturing Department of Mechanics and Aerospace EngineeringSouthern University of Science and TechnologyShenzhenP.R.China Department of Chemistry City University of Hong KongHong KongP.R.China Department of Respiratory and Critical Care Medicine Peking University Shenzhen HospitalShenzhenGuangdongP.R.China

As the first version of synthetic hydrogel,poly(2-hydroxyethyl methacrylate)hydrogels have found broad ***,their poor mechanical performances have been longstanding hurdles for practical ***,we report on strengthening the poly(2-hydroxyethyl methacrylate)hydro-gels with biochar nanoparticles and hydrophobic aggregations,which are induced by solvent exchange and reinforced by *** the vast anchoring points on the multifunc-tional surfaces of the biochar nanoparticles and the aggregates formed between poly(2-hydroxyethyl methacrylate)chains engender strong and dissipative physical *** result-ing hydrogels exhibit marked mechanical properties,encom-passing high stretchability~7,high fracture toughness~1360 J m−2,high elastic modulus~180 kPa,low friction coefficient~0.2,self-recovery,and ***,we demonstrate the versatility of the proposed strategy by using water/ionic liquid binary solvent as the sol-vent system,Laponite as the nano-reinforcement,and dryanneal as the hydrophobic aggregation enhancer to synthesize mechanically robust ***(2-hydroxyethyl methacry-late)hydrogels of superior mechanical properties are expected to enable previously inaccessible applications in biomedicine and engineering.

关键词： Hydrogel PHEMA mechanical properties biochar hydrophobic aggregation

Multicolor upconversion reversible modulations in YNbO_(4):Er^(3+)/Tm^(3+)/Yb^(3+) photochromic materials

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Journal of Rare Earths 2024年第2期42卷 270-277,I0002页

作者： Zhen Zhang Peng Li ziyi xu Zhihao Zhang Qiwei Zhang Haiqin Sun Xihong Hao Inner Mongolia Key Laboratory of Ferroelectric-related New Energy Materials and Devices Schoolof Materials and MetallurgyInner Mongolia University of Science and TechnologyBaotou014010China College of Physics and Technology Guangxi Normal UniversityGuilin541004China

Photochromic materials with multicolor upconversion reversible modulations are attractive in optical switching ***,the fabricated YNbO_(4):Er^(3+)/Tm^(3+)/Yb^(3+) materials exhibit excellent photochromism and multicolor upconversion properties from green,red to near infrared(NIR) emissions with increasing Yb *** multiband upconversion modulations are achieved by alternating light(365 and 405 nm) or thermal *** 365 nm irradiation,the luminescence color changes from yellow to red,the luminescent photoswitching contrast reaches up to 86.21%(green),82.12%(red) and 77.38%(NIR) in the Y_(0.83)Er_(0.01)Tm_(0.01)NbO_(4):0.15 Yb ***,the upconversion emission intensity before and after photochromic reaction shows remarkable change in a wide temperature range of 298-718 *** results indicate that the Er^(3+)/Tm^(3+)/Yb^(3+) tri-doped YNbO_(4) materials can be a good candidate in optical switching and data storage applications.

关键词： Photochromic materials Luminescence modulation Multicolor emission Photoswitching contrast Rare earths

Identification of various food residuals on denim based on hyperspectral imaging system and combination optimal strategy

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Artificial Intelligence in Agriculture 2021年第1期5卷 125-132页

作者： Yuzhen Chen ziyi xu Wencheng Tang Menghan Hu Douning Tang Guangtao Zhai Qingli Li Shanghai Key Laboratory of Multidimensional Information Processing School of Communication&Electronic EngineeringEast China Normal UniversityShanghai 200062China School of Statistics East China Normal UniversityShanghai 200062China Institute of Image Communication and Information Processing Shanghai Jiao Tong UniversityShanghai 200240China McCormick School of Engineering Northwestern UniversityEvanstonILUnited States

As the science and technology develop,crime methods and scenes have become increasingly complex and *** evidence analysis has become amore and more important criminal investigation technology and liquid is the main form of trace *** can provide not only energy,but clues to solve *** this study,we build a hyperspectral imaging system to detect liquid residue traces,including apple juice,coffee,cola,milk and tea,on denims with light,middle and dark *** obtained hyperspectral images are first subjected to spectral calibration and hyperspectral data ***,Partial Least Squares(PLS)is applied to select the informative wavelengths from the preprocessed *** modeling phase,the combination optimal strategy,support vector machine(SVM)combined with random forest(RF),is developed to establish classification *** experimental results demonstrate that the combination optimal model can achieve TPR,FPR,Precision,Recall,F1,and AUC of 83.5%,2.30%,79.7%,83.5%,81.6%,and 94.7%for classifying fabrics contaminated by various food *** respect to the classification of liquid and fabric types,the combination optimalmodel also yields satisfactory classification *** future work,wewill expand the types of liquid,and make appropriate adjustment to algorithms for improving the robustness of classification *** research may play a positive role in the construction of a harmonious society.

关键词： Hyperspectral imaging Food residual on denim Combination optimal strategy Variable selection Forensic application

Adjuvant and neo‐adjuvant immunotherapy in resectable non‐small cell lung cancer (NSCLC): Current status and perspectives

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Cancer Innovation 2023年第1期2卷 65-78页

作者： ziyi xu Zihua Zou xuezhi Hao Puyuan Xing Junling Li Department of Medical Oncology National Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina Department of Medical Oncology Fujian Provincial Cancer HospitalFuzhouChina

Surgery followed by adjuvant chemotherapy is the standard of care for selectedpatients with early‐stage or locally advanced non‐small cell lung cancer(NSCLC). However, many of these patients still experience postoperativerecurrence at 5 years. At present, peri‐operative treatment methods areemerging to prevent early relapse, such as targeted therapy and *** on predictive biomarkers of responses to adjuvant andneoadjuvant therapies is also continuously ongoing. Immunotherapy representedby immune checkpoint inhibitors (ICIs), either by monotherapy or incombination with chemotherapy, has shown benefit in promoting pathologicalresponses and prolonging survival for patients with NSCLC without oncogenicmutations. Exploratory studies have also provided evidence regarding theselection of patients who benefit from ICI‐based perioperative treatment. Thisreview focuses on the existing data of current clinical trials of adjuvant andneoadjuvant strategies with ICIs in resectable NSCLC, the exploration ofpredictive biomarkers, and the perspectives and urgent challenges in thefuture.

关键词： biomarker peri‐operative immunotherapy resectable NSCLC

Temperature effect on nanotwinned Ni under nanoindentation using molecular dynamic simulation

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Chinese Physics B 2024年第1期33卷 603-612页

作者：何茜徐子翼倪玉山 Department of Aeronautics and Astronautics Fudan UniversityShanghai 200433China

Temperature effect on atomic deformation of nanotwinned Ni (nt-Ni) under localized nanoindentation is investigated in comparison with nanocrystalline Ni (nc-Ni) through molecular *** nt-Ni exhibits enhanced critical load and hardness compared to nc-Ni,where perfect,stair-rod and Shockley dislocations are activated at (111),(111) and (111) slip planes in nt-Ni compared to only SSockley dislocation nucleation at (111) and (111) slip planes of *** nt-Ni exhibits a less significant indentation size effect in comparison with nc-Ni due to the dislocation slips hindrance of the twin *** atomic deformation associated with the indentation size effect is investigated during dislocation *** from the decreasing partial slips parallel to the indenter surface in nc-Ni with increasing temperature,the temperaturedependent atomic deformation of nt-Ni is closely related to the twin boundary:from the partial slips parallel to the twin boundary (~10 K),to increased confined layer slips and decreased twin migration(300 K–600 K),to decreased confined layer slips and increased dislocation interaction of dislocation pinning and dissociation (900 K–1200 K).Dislocation density and atomic structure types through quantitative analysis are implemented to further reveal the above-mentioned dislocation motion and atomic structure *** study is helpful for understanding the temperature-dependent plasticity of twin boundary in nanotwinned materials.

关键词： nanoindentation twin boundary plastic deformation molecular dynamics simulation

Evolution of the historical polder landscape in the ancient Danyang wetland,lower Yangtze River,China,during the last 3000 years

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Journal of Geographical Sciences 2024年第10期34卷 2053-2073页

作者： HU Xiaosi WU Li ZHUANG Yijie WANG Xinyuan MA Chunmei LI Linying GUAN Houchun LU Shuguang LUO Wenjing xu ziyi Provincial Key Laboratory of Earth Surface Processes and Regional Response in the Yangtze-Huaihe River Basin School of Geography and TourismAnhui Normal UniversityWuhu 241002AnhuiChina Institute of Archaeology University College LondonLondon WC1H OPYUK Aerospace Information Research Institute CASBeijing 100094China School of Geographic and Oceanographic Sciences Nanjing UniversityNanjing 210023China Anhui Institute of Geological Sciences Hefei 230001China

Polder is a type of irrigation field unique to the lower Yangtze River of *** is a product of long-term and ingenuous human modifications of wetland *** the pre-Qin Period,3000 years ago,the poldered area of eastern Wuhu city was once a large lake called the ancient Danyang *** introduction of agricultural civilization and polder technology to the area during the Wu and Yue Kingdoms period gradually transformed it into an agricultural *** an accelerating rate of land reclamation under a changing late-Holocene regional climate,the ancient Danyang wetland became an aquatic system strongly influenced by intensifying anthropogenic *** this study,based on field survey data,historical documents,and remote-sensing and archaeological data,we reconstructed the spatial distribution of the polder landscape over the last 3000 years and identified their structural *** found that polder landscapes began to emerge in the Spring and Autumn Period,land reclamation intensified in the Three Kingdoms and developed rapidly in the Song Dynasty before eventually reaching the peak from the Ming and Qing *** relocation of historical sites to low-altitude areas also marked the expansion of poldered fields from the center of the wetland to the southeast and *** development and evolution of the polder landscape are related to regional climate conditions,changing social and economic statuses,and the development of agricultural technology in the Song Dynasty and succeeding periods.

关键词： ancient Danyang wetland polder landscape climate change anthropogenic activities lower Yangtze River

基于质谱和光谱分析的同位素气体检测技术研究进展

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激光与光电子学进展 2024年第13期61卷 22-33页

作者：许子怡刘硕河北工业大学电子信息工程学院先进激光技术研究中心天津300401

气体同位素丰度检测在工业生产、生物医疗、地质勘测等方面均具有重要的研究价值,能够应用于工业安全在线监控、依据人体呼出气体实时临床无创诊断等方面。首先介绍同位素气体检测技术的应用价值和应用领域,证实同位素气体检测具有广阔... 详细信息

气体同位素丰度检测在工业生产、生物医疗、地质勘测等方面均具有重要的研究价值,能够应用于工业安全在线监控、依据人体呼出气体实时临床无创诊断等方面。首先介绍同位素气体检测技术的应用价值和应用领域,证实同位素气体检测具有广阔的应用前景。接着阐述了同位素丰度的内涵,然后从质谱分析技术和光谱分析技术两方面出发,介绍了质谱分析、光声光谱、可调谐半导体激光吸收光谱、腔衰荡光谱和腔增强吸收光谱检测技术这五种同位素丰度探测手段,分别阐释了不同检测技术的相关原理和近年来同位素气体检测的研究进展。通过对比五种同位素丰度检测技术的性能,分析得到各同位素气体检测技术的优缺点和适用场景,并提出未来同位素气体检测技术的研究展望。

关键词：同位素丰度检测质谱分析光声光谱可调谐半导体激光吸收光谱腔衰荡光谱腔增强吸收光谱