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A promising approach to steady-state fusion: High-temperature superconducting strong-field stellarator with precise omnigenity

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The Innovation 2024年第1期5卷 23-25页

作者： Guosheng Xu zhiyuan Lu Dehong chen Baonian Wan Institute of Plasma Physics Chinese Academy of SciencesHefei 230031China

The stellarator has inherent advantages over the tokamak in achieving steady-state operation,especially due to its absence of disruptions and lack of need for current drive and the associated recirculating power.In recent years,there have been remarkable advances in the field of stellarator optimization,where precisely quasi-symmetric and precisely quasi-isodynamic magnetic configurations have been achieved with coils,allowing the neoclassical transport and energetic particle losses of stellarators to be reduced to levels comparable to those of tokamaks.At the same time,the development of high-temperature superconducting magnet technology will potentially double the magnetic field strength of stellarators.While these strong fields are expected to introduce new challenges,and while turbulent transport remains a common challenge for both stellarators and tokamaks,the combination of these physical and technological advances results in the expectation that stellarators will become a competitive approach to tokamaks for realizing steady-state fusion.

关键词： field approach precise

Effect of particle composition and consolidation degree on the wave-induced liquefaction of soil beds

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Acta Oceanologica Sinica 2024年第2期43卷 11-22页

作者： zhiyuan chen Yupeng Ren Guohui Xu Meng Li Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering Ocean University of ChinaQingdao 266100China Marine Ecological Restoration and Smart Ocean Engineering Research Center of Hebei Province Qinhuangdao 066000China Key Laboratory of Marine Environment and Ecology(Ocean University of China) Ministry of EducationQingdao 266100China Key Laboratory of Submarine Geoscience and Prospecting Techniques(Ocean University of China) Ministry of EducationQingdao 266100China

The wave-induced liquefaction of seabed is responsible for causing damage to marine structures.Particle composition and consolidation degree are the key factors affecting the pore water pressure response and liquefaction behavior of the seabed under wave action.The present study conducted wave flume experiments on silt and silty fine sand beds with varying particle compositions.Furthermore,a comprehensive analysis of the differences and underlying reasons for liquefaction behavior in two different types of soil was conducted from both macroscopic and microscopic perspectives.The experimental results indicate that the silt bed necessitates a lower wave load intensity to attain the liquefaction state in comparison to the silty fine sand bed.Additionally,the duration and development depth of liquefaction are greater in the silt bed.The dissimilarity in liquefaction behavior between the two types of soil can be attributed to the variation in their permeability and plastic deformation capacity.The permeability coefficient and compression modulus of silt are lower than those of silty fine sand.Consequently,silt is more prone to the accumulation of pore pressure and subsequent liquefaction under external loading.Prior research has demonstrated that silt beds with varying consolidation degrees exhibit distinct initial failure modes.Specifically,a dense bed undergoes shear failure,whereas a loose bed experiences initial liquefaction failure.This study utilized discrete element simulation to examine the microscopic mechanisms that underlie this phenomenon.

关键词： wave flume liquefaction pore water pressure consolidation permeability experiment discrete element simulation

Experimental investigation about the incipient velocity of spherical particles on a hemispherical bed surface

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Particuology 2024年第5期88卷 49-61页

作者： Chuannan Li Jie chen Changbo Jiang Xie Li zhiyuan Wu School of Hydraulic and Environmental Engineering Changsha University of Science & TechnologyChangsha 410114China Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province Changsha 410114China Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province Changsha 410114China

The sediment particles play a huge role in shaping the bed load transport.In this research,240 water-tunnel experiments are carried out to investigate the incipient velocity of the observation particles in two particle arrangements.To accurately predict the incipient velocity of the observation particles,the equation is conceived by the rolling instability mechanism.The incipient velocity equations and experimental data are used to analyze the trend of dispersive pressure and the effect of arrangement position on velocity.We find that it is appropriate to choose the coefficient of drag as 0.261 and the coefficient of lift as 0.198 for the incipient velocity equation of spherical particles on the hemispherical bed surface.Furthermore,the dispersive pressure is closely related to the flow state,particle size,and particle arrangement,which leads to the incipient velocity of the observation particle being at a minimum when the interference particle angle is 45°.Finally,the particle spacing and the projected area changed with the arrangements,directly affecting the incipient velocity of the observed particle.The analysis of four aspects for the coefficients,dispersive pressure,different particle spacing,and projected area will facilitate the prediction of particle incipient velocity,especially on hemispherical beds.

关键词： Hemispherical bed surface Observed particle Interference particle Dispersive pressure Incipient velocity

Multi-blade rubbing characteristics of the shaft-disk-blade-casing system with large rotation

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 111-136页

作者： zhiyuan WU Linchuan ZHAO Han YAN Ge YAN Ao chen Wenming ZHANG State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China Shanghai Institute of Aerospace Systems Engineering Shanghai 201108China

Blade rubbing faults cause detrimental impact on the operation of aeroengines. Most of the existing studies on blade rubbing in the shaft-disk-blade-casing(SDBC) system have overlooked the elastic deformation of the blade, while some only consider the whirl of the rotor, neglecting its spin. To address these limitations, this paper proposes a dynamic model with large rotation for the SDBC system. The model incorporates the spin and whirl of the rotor, enabling the realistic reproduction of multiblade rubbing faults. To verify the accuracy of the SDBC model with large rotation and demonstrate its capability to effectively consider the rotational effects such as the centrifugal stiffening and gyroscopic effects, the natural characteristics and dynamic responses of the proposed model are compared with those obtained from reported research and experimental results. Furthermore, the effects of the rotating speed, contact stiffness,and blade number on the dynamic characteristics of the SDBC system with multi-blade rubbing are investigated. The results indicate that the phase angle between the rotor deflection and the unbalance excitation force increases with the increasing rotating speed,which significantly influences the rubbing penetration of each blade. The natural frequency of the SDBC system with rubbing constrain can be observed in the acceleration response of the casing and the torsional response of the shaft, and the frequency is related to the contact stiffness. Moreover, the vibration amplitude increases significantly with the product of the blade number under rubbing, and the rotating frequency approaches the natural frequency of the SDBC system. The proposed model can provide valuable insight for the fault diagnosis of rubbing in bladed rotating machinery.

关键词： shaft-disk-blade-casing(SDBC) large rotation spin and whirl multi-blade rubbing rotational effect

Design and test of the arc-shaped nail-tooth roller residual film recovery machine from the sowing layer

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International Journal of Agricultural and Biological Engineering 2024年第1期17卷 90-98页

作者： zhiyuan Zhang Xuegeng chen Xianfei Wang Shuaikang Xue Jingbin Li College of Mechanical and Electrical Engineering Shihezi UniversityShihezi 832003XinjiangChina Xinjiang Production and Construction Corps Key Laboratory of Modern Agricultural Machinery Shihezi 832003XinjiangChina Key Laboratory of Northwest Agricultural equipment Ministry of Agriculture and Rural AffairsShihezi 832003XinjiangChina

Residual films on the sowing layer produced after mulching in Xinjiang farmland,harm the sowing quality and root growth of crops.In this study,a sowing layer residual film recovery machine based on a radial plate arc-shaped nail-tooth roller structure was designed.Meanwhile,the key device structures were designed and the main working parameters were analyzed.Then,taking the working depth,the forward speed of the machine and the rotation speed of the nail tooth roller as the test factors,and the film collection rate and film intertwining rate as the test indicators,the single factor tests and the Box-Behnken response surface tests were carried out to evaluate the performance of the sowing layer residual film recovery machine.Consequently,the results showed that the order of significant factors was the working depth,the forward speed of the machine,and the rotation speed of the nail tooth roller.Besides,the optimal working parameters were determined,which the working depth,the forward speed of the machine,and the rotation speed of the nail tooth roller were 100 mm,4.8 km/h,and 49.3 r/min,respectively.Moreover,the predicted value of the film collection rate was 69.20%.Finally,the verification test was taken with the optimal working parameter,and the results showed that the film collection rate was 66.84%,and the film intertwining rate was 1.39%.The relative error between the test value and the predicted value of the film collection rate was 3.40%.It indicated that the machine can perform the collection of sowing layer residual films.This study can provide a theoretical basis and reference for the design of new sowing layer residual film machines.

关键词： residual film recycling machine mulching film pick-up device seedbed preparation

Electrohydrodynamic printing for high resolution patterning of flexible electronics toward industrial applications

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InfoMat 2024年第2期6卷 28-56页

作者： Zhouping Yin Dazhi Wang Yunlong Guo zhiyuan Zhao Liqiang Li Wei chen Yongqing Duan State Key Laboratory of Intelligent Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhanthe People's Republic of China Optics Valley Laboratory Wuhanthe People's Republic of China Key Laboratory for Micro/Nano Technology and System of Liaoning Province Dalian University of TechnologyDalianthe People's Republic of China Beijing National Laboratory for Molecular Sciences Key Laboratory of Organic SolidsInstitute of ChemistryChinese Academy of SciencesBeijingthe People's Republic of China Institute of Molecular Aggregation Sciences Tianjin UniversityTianjinthe People's Republic of China

Electrohydrodynamic(EHD)printing technique,which deposits micro/nanostructures through high electric force,has recently attracted significant research interest owing to their fascinating characteristics in high resolution(<1μm),wide material applicability(ink viscosity 1–10000 cps),tunable printing modes(electrospray,electrospinning,and EHD jet printing),and compatibility with flexible/wearable applications.Since the laboratory level of the EHD printed electronics'resolution and efficiency is gradually approaching the commercial application level,an urgent need for developing EHD technique from laboratory into industrialization have been put forward.Herein,we first discuss the EHD printing technique,including the ink design,droplet formation,and key technologies for promoting printing efficiency/accuracy.Then we summarize the recent progress of EHD printing in fabrication of displays,organic field-effect transistors(OFETs),transparent electrodes,and sensors and actuators.Finally,a brief summary and the outlook for future research effort are presented.

关键词： display electrohydrodynamic printing flexible electronics organic field-effect transistor printhead

ZmCYP90D1 regulates maize internode development by modulating brassinosteroid-mediated cell division and growth

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The Crop Journal 2024年第1期12卷 58-67页

作者： Canran Sun Yang Liu Guofang Li Yanle chen Mengyuan Li Ruihua Yang Yongtian Qin Yongqiang chen Jinpeng cheng Jihua Tang zhiyuan Fu Key Laboratory of Wheat and Maize Crops Science/Collaborative Innovation Center of Henan Grain Crops/College of Agronomy Henan Agricultural UniversityZhengzhou 450046HenanChina The Shennong Laboratory Zhengzhou 450002HenanChina Hebi Academy of Agricultural Sciences Hebi 458030HenanChina Yunnan Tang Jihua Expert Workstation/Zhaotong Academy of Agricultural Sciences Zhaotong 657000YunnanChina

Plant height(PH)is associated with lodging resistance and planting density,which is regulated by a complicated gene network.In this study,we identified a spontaneous dwarfing mutation in maize,m30,with decreased internode number and length but increased internode diameter.A candidate gene,ZmCYP90D1,which encodes a member of the cytochrome P450 family,was isolated by map-based cloning.ZmCYP90D1 was constitutively expressed and showed highest expression in basal internodes,and its protein was targeted to the nucleus.A G-to-A substitution was identified to be the causal mutation,which resulted in a truncated protein in m30.Loss of function of ZmCYP90D1 changed expression of hormoneresponsive genes,in particular brassinosteroid(BR)-responsive genes which is mainly involved in cell cycle regulation and cell wall extension and modification in plants.The concentration of typhasterol(TY),a downstream intermediate of ZmCYP90D1 in the BR pathway,was reduced.A haplotype conferring dwarfing without reducing yield was identified.ZmCYP90D1 was inferred to influence plant height and stalk diameter via hormone-mediated cell division and cell growth via the BR pathway.

关键词： Maize ZmCYP90D1 BR biosynthesis Dwarf plant

UAV safe route planning based on PSO-BAS algorithm

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Journal of Systems Engineering and Electronics 2022年第5期33卷 1151-1160页

作者： ZHANG Honghong GAN Xusheng LI Shuangfeng chen zhiyuan Air Traffic Control and Navigation College Air Force Engineering UniversityXi’an 710051China National Key Laboratory of Air Traffic Collision Prevention Xi’an 710051China

In order to solve the current situation that unmanned aerial vehicles(UAVs)ignore safety indicators and cannot guarantee safe operation when operating in low-altitude airspace,a UAV route planning method that considers regional risk assessment is proposed.Firstly,the low-altitude airspace is discretized based on rasterization,and then the UAV operating characteristics and environmental characteristics are combined to quantify the risk value in the low-altitude airspace to obtain a 3D risk map.The path risk value is taken as the cost,the particle swarm optimization-beetle antennae search(PSO-BAS)algorithm is used to plan the spatial 3D route,and it effectively reduces the generated path redun􀅫dancy.Finally,cubic B-spline curve is used to smooth the plan􀅫ned discrete path.A flyable path with continuous curvature and pitch angle is generated.The simulation results show that the generated path can exchange for a path with a lower risk value at a lower path cost.At the same time,the path redundancy is low,and the curvature and pitch angle continuously change.It is a flyable path that meets the UAV performance constraints.

关键词： unmanned aerial vehicle(UAV) low-attitude airspace mission planning risk assessment particle swarm optimization beetle antennae search(BAS) cubic B-spline

Updated prevalence of latent prostate cancer in Chinese population and comparison of biopsy results: An autopsy-based study

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The Innovation 2024年第1期5卷 80-87页

作者： Yuliang chen Zhien Zhou Yi Zhou Zhipeng Mai Shijie Jin Zhen Liang zhiyuan Shang Yuzhi Zuo Yu Xiao Wenze Wang Haibo Wang Weigang Yan Department of Urology Peking Union Medical College HospitalChinese Academy of Medical SciencesBeijing 100730China Department of Gynaecology and Obstetrics Beijing HospitalNational Centre of GerontologyBeijing 100730China Department of Pathology Peking Union Medical College HospitalChinese Academy of Medical SciencesBeijing 100730China Peking University Clinical Research Institute Peking University First HospitalBeijing 100034China

Prostate cancer detected by autopsy is named latent prostate cancer.As the repertoire of clinical prostate cancer,latent cancer may better reflect the disease burden.Unlike clinical prostate specimens,which are obtained exclusively from biopsy-positive cases,prostate specimens obtained through autopsy provide information on biopsy-negative cases,helping calculate the true sensitivity of prostate biopsy.From 2014 to 2021,we collected autopsy specimens of the prostate from body donors in China and performed transperineal and transrectal biopsies on specimens before step-sectioning and pathological measurements.We found that the crude prevalence of latent prostate cancer in middle-aged and elderly men was 35.1%(81/231),which was higher than previous estimates for Chinese populations.The overall per-patient sensitivities of transperineal and transrectal biopsies were not significantly different(33.3%vs.32.1%,p=0.82),but the two approaches differed in preferential sampling area along the proximal-distal axis of the prostate.Transperineal biopsy had a higher sensitivity for detecting clinically significant lesions in the distal third(34.7%vs.16.3%,p=0.02)and distal half(30.6%vs.18.1%,p=0.04),while transrectal biopsy had a higher sensitivity for lesions in the proximal half(25.0%vs.13.9%,p=0.046).Both transperineal and transrectal methods of biopsy missed most small lesions(0.5 mL).In conclusion,the prevalence of latent prostate cancer in China has increased over the past 2 decades.Systematic transperineal and transrectal methods of biopsy had comparable sensitivities but had different preferential sampling areas.Both approaches miss one-third of large lesions.

关键词： biopsy prevalence latent