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Optimization of a Lobed Mixer with BP Neural Network and Genetic Algorithm

Journal of Thermal Science 2023年第1期32卷 387-400页

作者： SONG Yukuan LEI Zhijun lu Xin-Gen XU Gang ZHU Junqiang Key Laboratory of Light-Duty Gas Turbine Institute of Engineering ThermophysicsChinese Academy of SciencesBeijing 100190China School of Aeronautics and Astronautics University of Chinese Academy of SciencesBeijing 100049China

A Sequential Approximate Optimization framework(SAO)for the multi-objective optimization of lobed mixer is established by using the BP neural network and Genetic Algorithm:the ratio of lobe wavelength to height(η)and the rise angle(α)are selected as the design parameters,and the mixing efficiency,thrust and total pressure loss are the optimization *** CFX commercial solver coupled with the SST turbulence model is employed to simulate the flow field of lobed mixer.A tetrahedral unstructured grid with 5.6 million cells can achieve the similar global *** on the response surface approximation model of the lobed mixer,it is necessary to avoid increasing or decreasingαandηat the same ***,theαshould be reduced while theηis appropriately increased,which is conducive to achieving the goal of increasing thrust and reducing losses at the expense of a small decrease in the mixing *** with the normalized method,the non-normalized method with better global optimization accuracy is more suitable for solving the multi-objective optimization problem of the lobed mixer,and its optimal solution(α=8.54°,η=1.165)is the optimal solution of the lobed mixer optimization problem studied in this *** with the reference lobed mixer,theα,β(the fall angle)and H(lobe height)of the optimal solution are reduced by 0.14°,1.34°and 3.97 mm,respectively,and theηis increased by 0.074;its mixing efficiency is decreased by 4.46%,but the thrust is increased by 2.29%and the total pressure loss is decreased by 0.64%.Downstream of the optimized lobed mixer,the radial scale and peak vorticity of the streamwise voritices decrease with the decreasing lobe height,thereby reducing the mixing *** the optimized lobed mixer,its low mixing efficiency is the main factor for the decrease of the total pressure loss,but the improvement of the geometric curvature is also conducive to reducing its profile *** the scope of this study,the lobed mixer

关键词： lobed mixer optimization BP neural network genetic algorithm jet mixing

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一种复杂空间飞网系统参数优化设计方法

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航空学报 2016年第10期37卷 3064-3073页

作者：王晓慧万长煌夏人伟北京航空航天大学宇航学院北京100083

由轻质软绳索编织而成的空间飞网是为非合作目标捕获而提出的空间系统概念,在空间碎片和废弃航天器处理方面具有很大的应用潜力。从平台抛射出后,飞网在空间形成不稳定的网形,且网形变化规律受初始参数设计的影响较大。针对空间飞网系... 详细信息

由轻质软绳索编织而成的空间飞网是为非合作目标捕获而提出的空间系统概念,在空间碎片和废弃航天器处理方面具有很大的应用潜力。从平台抛射出后,飞网在空间形成不稳定的网形,且网形变化规律受初始参数设计的影响较大。针对空间飞网系统设计与试验中系统参数匹配问题,本文提出以容错值作为飞网展开性能的定量描述,从捕获任务的层面,建立面向捕获容错的空间飞网系统参数优化数学模型;以抓捕固定距离、确定大小的目标任务为算例,联合Isight优化平台与ANSYS/LS-Dyna求解,得到飞网系统最优参数匹配,算例仿真结果表明结果的适用性;最后,利用试验设计和极差分析方法验证最优点的稳定性。研究的模型与方法为开展空间飞网系统地面及空间试验等工程应用提供理论依据。

关键词：空间飞网系统参数匹配优化模型容错值实验设计

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Characteristics of Late Quaternary Activity of the Gadê Segment in the Madoi-Gadê Fault Zone

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Earthquake Research in China 2011年第2期25卷 201-212页

作者： Xiong renwei Ren Jinwei Zhang Junlong Yang Panxin Li Zhimin Hu Chaozhong Chen Changyun Institute of Earthquake Science CEA Beijing 100036 China Earthquake Administration of Qinghai Province Xining $10001 China

Madoi-Gade fault is an active fault in the Bayan Har block. According to field investigation, there is an earthquake surface rupture fairly well preserved on the Gade segment of the Madoi-Gade fault zone. The length of the rupture is approximately 50km, with a general strike of NW. The maximum horizontal sinistral displacement is about 7.6m and the maximum vertical displacement is about 4m. A large number of earthquake traces are to be found along the rupture zone, and the phenomena on the surface rupture are also various. Field investigation and analysis on the geological and geomorphological phenomena show that the formation age of the surface rupture is relatively young. A series of linear arranged, triangular facets, fault scarps, fault springs, dislocated gullies, twisted mountain ridges, sag-ponds, dislocated ridges, etc. exist along the fault. Based on the analysis of field investigation and the data available, we believe that the surface rupture is due to a strong earthquake in the history of this area. And it is inferred that the Madoi- Gade fault within the Bayan Har block has been highly active since Late Quaternary and may still be active nowadays.

关键词： Madoi-Gade fault Earthquake rupture Bayan Har block Late Quaternary

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Urban Systems:Understanding and Predicting the Spatial Distribution of China's Population

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China & World Economy 2021年第4期29卷 35-62页

作者： Pengfei Li Ming lu Antai College of Economics and Management Shanghai Jiao Tong UniversityChina China Institute for Urban Governance Shanghai Jiao Tong UniversityChina

With urbanization and population migration,some Chinese cities fall into decline whereas others *** nighttime light data,we redefine the city based on economic function and evaluate the city size distribution in representative *** results provide evidence not only for Zipfs law,but also for a distortion in China s current city size *** study proposes a feasible method to predict urban population distribution based on the role of geographical factors in regional development,following the idea of spatial *** prediction suggests that the divergence of city size in China tends to be pronounced,with inter-regional income disparity being narrowed and the city size distribution following Zipfs *** Chinese government should further relax restrictions on population inflow into large cities and prepare for more migration in the future.

关键词： geographical factors population distribution urban system Zipf's law

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化疗诱导的周围神经病变的发病机制及治疗进展

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中国药理学通报 2025年第1期41卷 18-22页

作者：陆新曲琳卓王勇关宏锏吴艳玲延边大学附属医院神经内科吉林延吉133002 延边大学药学院长白山天然药物研究教育部重点实验室吉林延吉133002

化疗诱导的周围神经病变(chemotherapy-induced peripheral neuropathy,CIPN)是指使用抗肿瘤药物导致外周神经功能紊乱而表现出来的一些症状与体征,与化疗药物呈剂量相关性。CIPN的发病机制尚未完全明确,且现有的治疗药物和治疗方法疗... 详细信息

化疗诱导的周围神经病变(chemotherapy-induced peripheral neuropathy,CIPN)是指使用抗肿瘤药物导致外周神经功能紊乱而表现出来的一些症状与体征,与化疗药物呈剂量相关性。CIPN的发病机制尚未完全明确,且现有的治疗药物和治疗方法疗效有限,因此探究CIPN的发病机制、研发新的治疗药物和治疗方法,解决未被满足的临床需求具有重要科学价值和社会意义。该文将从分子和细胞层面阐述CIPN的发病机制,以及对CIPN的治疗进展进行综述,为临床治疗提供参考,为未来研究提供方向。

关键词：化疗诱导的周围神经病变外周神经毒性化疗诱导疾病药物相关性副作用和不良反应中医药疗法中医药熏洗疗法

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Numerical Investigation of a Centrifugal Compressor with a Pre-Compression Wedge Diffuser under High Subsonic Conditions

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Journal of Thermal Science 2020年第4期29卷 945-954页

作者： WANG Yi LI Qingkuo BAI Huan ZHOU Xueqi lu Xin’gen School of Aeronautics and Astronautics Central South UniversityChangsha 410083China AECC Hunan Aviation Powerplant Research Institute Hunan Key Laboratory of Turbomachinery on Small and Medium Areo-EngineZhuzhou 412002China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China

As the total pressure ratio of centrifugal compressors increases, the diffuser inlet flow becomes highly subsonic or even supersonic, which causes additional shock loss. The shock loss leads the stage performance to drop greatly. Pre-compression is an efficient method for reducing shock loss and improving the stage performance. To study the effect of wedge diffusers with pre-compression blades on centrifugal compressor performance, wedge diffusers with various pre-compression angles, divergence angles and numbers of blades were designed and investigated via a numerical method. As a result, it is found that the compressor stage achieves high peak efficiency when the pre-compression angle ranges from 2.5° to 5.5° and when the divergence angle ranges from 7° to 9°. As the number of blades increases, the total pressure ratio and adiabatic efficiency of the compressor stage increase slightly, whereas the surge margin of the stage decreases.

关键词： wedge diffuser pre-compression high Subsonic centrifugal compressor

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Inverse design with deep generative models: next step in materials discovery

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National Science Review 2022年第8期9卷 15-17页

作者： Shuaihua lu Qionghua Zhou Xinyu Chen Zhilong Song Jinlan Wang School of Physics Southeast University

In the past few years, machine-learning(ML) techniques have been extensively applied in material discovery. Such techniques are applied to minimize the computationally or experimentally expensive costs of the research process, greatly reducing overall design time [1]. Typically,ML algorithms are combined with traditional methods like first-principle calculations to accelerate the optimization of compositions on the known crystal structures(elemental substitution) in the database or literature, or to search for new configurations of a fixed chemical composition.

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Safety-Critical Model-Free Control for Multi-Target Tracking of USVs with Collision Avoidance

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IEEE/CAA Journal of Automatica Sinica 2022年第7期9卷 1323-1326页

作者： Shengnan Gao Zhouhua Peng Haoliang Wang lu Liu Dan Wang School of Marine Electrical Engineering Dalian Maritime UniversityDalian 116026China School of Marine Engineering Dalian Maritime UniversityDalian 116026China IEEE

Dear editor,This letter addresses the multi-target tracking of underactuated unmanned surface vehicles(USVs)subject to multiple stationary/moving *** kinetic model parameters of each USV are totally unknown.A safety-critical model-free control method is proposed for tracking multiple targets with a collision-free containment ***,a distributed containment extended state observer(DCESO)is designed to estimate the convex hull spanned by the multiple *** the kinematic level,a collision-free kinematic guidance law is presented using a control barrier function(CBF)and an extended state observer for each follower *** the kinetic level,a model-free position tracking control law by using an adaptive ESO(AESO)is presented for each follower *** the designed safety-critical model-free control method,cooperative tracking of multiple targets under multiple stationary/moving obstacles can be achieved using completely unknown kinetic model *** are provided to illustrate the efficacy of the proposed safety-critical model-free control method for a fleet of USVs.

关键词： stationary collision totally

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Fast least-squares prestack time migration via accelerating the explicit calculation of Hessian matrix with dip-angle Fresnel zone

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Petroleum Science 2022年第3期19卷 1031-1047页

作者： Bo-Wu Jiang Jiang-Jie Zhang Hao Zhang Wen-Kai lu College of Mechanical and Electrical Engineering Beijing University of Chemical TechnologyBeijing100029China The Institute for Artificial Intelligence(THUAI) Beijing100084China State Key Laboratory of Intelligent Technology and Systems Beijing100084China Beijing National Research Center for Information Science and Technology(BNRist) Beijing100084China The Department of Automation Tsinghua UniversityBeijing100084China Key Laboratory of Petroleum Resource Research Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China Institute of Geomechanics Chinese Academy of Geological SciencesBeijing100081China

Amplitude versus offset analysis is a fundamental tool for determining the physical properties of reservoirs but generally hampered by the blurred common image gathers(CIGs).The blurring can be optimally corrected using the blockwise least-squares prestack time migration(BLS-PSTM),where common-offset migrated sections are divided into a series of blocks related to the explicit offsetdependent Hessian matrix and the following inverse filtering is iteratively applied to invert the corresponding ***,calculating the Hessian matrix is *** present a fast BLS-PSTM via accelerating Hessian calculation with dip-angle Fresnel zone(DFZ).DFZ is closely related to optimal migration aperture,which significantly attenuates migration swings and reduces the computational cost of ***,our fast BLS-PSTM is implemented as a two-stage ***,we limit the aperture for any imaging point with an approximated the projected Fresnel zone before calculating the Hessian ***,we determine whether a seismic trace contributes to the imaging point via DFZ during calculating the Hessian *** tests on synthetic and field data validate the distinct speedup with higher-quality CIGs compared to BLS-PSTM.

关键词： Prestack time migration Fresnel zone Hessian Least squares migration Migrated gather

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Optical coherence tomography angiography of optic disc perfusion in non-arteritic anterior ischemic optic neuropathy

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International Journal of Ophthalmology(English edition) 2017年第9期10卷 1402-1406页

作者： Jia-Wen Ling Xue Yin Qian-Yi lu Yi-Yi Chen Pei-Rong lu Department of Ophthalmology the First Affiliated Hospital of Soochow University Department of Ophthalmology the Third People's Hospital of Zhangjiagang

AIM：To compare the optic disc blood flow of non-arteritic ischemic optic neuropathy（NAION）eyes with normal ***：The optic disc blood flow densities of diagnosed non-acute phase NAION eyes（21 eyes,14 individuals）and normal eyes（19 eyes,12 individuals）were detected via Optovue optical coherence tomography angiography（OCTA）.The optic disc blood flow was measured via Image J *** between optic disc perfusion and visual function variables were assessed by linear regression ***：The average percentage of the optic disc nonperfusion areas in the non-acute phase NAION patients（17.84%±6.18%）was increased,when compared to the normal control eyes（8.61%±1.65%）,and the difference was statistically significant（P〈0.01）.Moreover,there was a proportional correlation between the visual field mean defect（MD）and the optic disc non-perfusion area percentage,and the relationship was statistically significant（t=3.65,P〈0.01,R2=0.4118）.In addition,the critical correlation between the best corrected visual acuity（BCVA）and the optic disc non-perfusion area percentage was statistically significant（t=4.32,P〈0.01,R2=0.4957）.CONCluSION：The optic disc non-perfusion area percentages detected via OCTA in NAION eyes were significantly increased when compared with the normal *** the BCVA and MD were correlated with the optic disc flow detected,revealing that OCTA may be valuable in the diagnosis and estimation of NAION.

关键词： non-arteritic anterior ischemic optic neuropathy optical coherence tomography angiography visual field visualacuity

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