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Three-dimensional dynamics of a single bubble rising near a vertical wall:Paths and wakes

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Petroleum Science 2023年第3期20卷 1874-1884页

作者： Hong-jie Yan he-Yang Zhang Hui-Min Zhang yi-xiang Liao Liu Liu School of Energy Science and Engineering Central South UniversityChangsha410083PR China Institute of Fluid Dynamics Hemholtz-zentrum Dresden-RossendorfD-01328DresdenGermany

In order to clarify the migration mechanism and wake behavior of a single bubble rising near a vertical wall,three-dimensional direct numerical simulations are implemented based on the open-source soft-ware Basilisk and various types of migration paths like linear,zigzag and spiral are *** volume of fluid(VOF)method is used to capture the bubble interface at a small scale,while the gas-liquid interface and high-velocity-gradient regions in the flow field are encrypted with the adaptive mesh refinement *** results show that the vertical wall has an obstructive effect on the diffusion of the vortex boundary layer on the surface of the bubble migrating in a straight line,and the resulting reaction force tends to push the bubbles away from the wall *** the zigzag or spiral movement of a bubble in the x-y plane,the perpendicular wall is an unstable factor,but on the contrary,the motion in the z-y plane is stabilized.

关键词： Bubble Wall effect Trajectory Wake structure VOF Basilisk

Performance Evaluation of List Sphere Detector

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Journal of Shanghai Jiaotong university(Science) 2005年第4期10卷 344-348页

作者： he xiang（贺翔） LUO Han-wen（罗汉文） yi Yang（易洋） Dept. of Electrical Eng. Shanghai Jiaotong Univ. Shanghai 200030 China

A list sphere detector can use a smaller list than commonly believed by employing an appropriate soft output approximation method. Its effect on the ＂quality＂ of detector＇s soft output value is evaluated by measuring mutual information under ergodic channel. The result shows a length 40 list is adequate for a 4×4 16QAM MIMO system without system-level iteration. For the ergodic channel, the gain of a sphere detector over the linear MMSE detector is dependent on channel coding rate, which answers an important question when sphere detector should he used in system level design. All these theoretical results are then verified by Monte Carlo simulation.

关键词： multiple-input multiple-output (MIMO) list sphere detector mutual information

Residual stress in the cylindrical drawing cup of SUS304 stainless steel evaluated by split-ring test

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Acta Mechanica Sinica 2016年第1期32卷 125-134页

作者： Liang-Hong Xiao Dao-he Yuan Jun-Zhong xiang Jin-Gang Liu yi-Chun Zhou School of Mechanical Engineering Xiangtan University Key Laboratory of Low Dimensional Materials & Application Technology Xiangtan University Ministry of Education

The residual stresses in the wall of a SUS304 stainless steel cylindrical drawing cup were evaluated by split-ring tests, and the influences of stamping die parame- ters on the residual stress were investigated. A new theoretical model of a split-ring test was developed to evaluate the resid- ual stress in a ring, which was verified to be reasonable and reliable by numerical simulations with ABAQUS code and by nanoindentation tests. Seven groups of split-ring tests were completed, and the residual stresses were calculated according to the theoretical model. The split-ring test results showed that the circumferential residual stress in the wall of the SUS304 stainless steel cylindrical drawing cup was very large and did not change with the different die comer radius. The circumferential residual stress first increased with the increase of drawing punch-die clearance, then was almost unchanged when the clearance increased greater than blank thickness 1 mm. Thus, a smaller clearance was suggested to be chosen to reduce the residual stress in the wall of the SUS304 stainless steel drawing cup.

关键词： Residual stress Split-ring test FEM numericalsimulation SUS304 stainless steel Nanoindentation

Proportional directional valve based automatic steering system for tractors

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Frontiers of Information Technology & Electronic Engineering 2016年第5期17卷 458-464页

作者： Jin-yi LIU Jing-quan TAN En-rong MAO Zheng-he SONG Zhong-xiang ZHU Beijing Key Laboratory of Optimized Design for Modern Agricultural Equipment China Agricultural University

Most automatic steering systems for large tractors are designed with hydraulic systems that run on either constant flow or constant pressure. Such designs are limited in adaptability and applicability. Moreover, their control valves can unload in the neutral position and eventually lead to serious hydraulic leakage over long operation periods. In response to the problems noted above, a multifunctional automatic hydraulic steering circuit is presented. The system design is composed of a 5-way-3-position proportional directional valve, two pilot-controlled check valves, a pressure-compensated directional valve, a pressurecompensated flow regulator valve, a load shuttle valve, and a check valve, among other components. It is adaptable to most open-center systems with constant flow supply and closed-center systems with load feedback. The design maintains the lowest pressure under load feedback and stays at the neutral position during unloading, thus meeting the requirements for steering. The steering controller is based on proportional-integral-derivative(PID) running on a 51-microcontroller-unit master control chip. An experimental platform is developed to establish the basic characteristics of the system subject to stepwise inputs and sinusoidal tracking. Test results show that the system design demonstrates excellent control accuracy, fast response, and negligible leak during long operation periods.

关键词： Automatic steering system Hydraulic circuit Proportional directional valve Proportional-integral-derivative(PID) control

Synthesis of Vitamin E Succinate from Candida rugosa Lipase in Organic Medium

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Chemical Research in Chinese Universities 2013年第2期29卷 223-226页

作者： JIANG xiang-jun HU yi JIANG Ling GONG Ji-hong HUANG he School of Biotechnology and Pharmaceutical Engineering Nanjing University of Technology Nanjing 210009 P. R. China

A screening of commercially available lipases for the synthesis of vitamin E succinate showed that lipase from Candida rugosa presented the highest yield. The synthesis of vitamin E succinate in organic solvents with dif- ferent lgP values ranging from -1.3 to 3.5 was investigated. Of particular interest was that dimethyl sulfoxide （DMSO） with the lowest lgP exhibited the highest yield among all the organic solvents used. It suggests that lgP is incapable of satisfactorily predicting the biocompatibility of organic solvents due to the complexity of enzymatic reaction with hydrophilic and hydrophobic substrates in organic solvent. Effects of different operating conditions, such as molar ratio of substrate, enzyme concentration, reaction temperature, mass transfer, and reaction time were also studied. Under the optimum conditions of 10 g/L enzyme, a stirring rate of 100 r/min, a substrate molar ratio of 5：1 at 55℃ for 18 h, a satisfactory yield（46.95%） was obtained. The developed method has a potential to be used for efficient enzymatic production of vitamin E succinate.

关键词： Vitamin E succinate Candida rugosa lipase Operating condition

Online soft measurement for wastewater treatment system based on hybrid deep learning

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Frontiers of Environmental Science & Engineering 2024年第2期18卷 77-89页

作者： Wenjie Mai Zhenguo Chen Xiaoyong Li Xiaohui yi yingzhong Zhao Xinzhong he xiang Xu Mingzhi Huang SCNU Environmental Research Institute Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety&MOE Key Laboratory of Theoretical Chemistry of EnvironmentSchool of EnvironmentSouth China Normal UniversityGuangzhou 510006China Fujian Environmental Protection Design Institute Co.Ltd. Fuzhou 350000China Huashi(Fujian)Environment Technology Co.Ltd. Quanzhou362001China SCNU Qingyuan Institute of Science and Technology Innovation Co.Ltd. Qingyuan 511517China Econ Technology Co.Ltd. Yantai 265503China

The existing automated wastewater treatment control systems encounter challenges such as the utilization of specialized testing instruments, equipment repair complications, high operational costs, substantial operational errors, and low detection accuracy. An effective soft measure model offers a viable approach for real-time monitoring and the development of automated control in the wastewater treatment process. Consequently, a novel hybrid deep learning CNN-BNLSTM-Attention (CBNLSMA) model, which incorporates convolutional neural networks (CNN), bidirectional nested long and short-term memory neural networks (BNLSTM), attention mechanisms (AM), and Tree-structure Parzen Estimators (TPE), has been developed for monitoring effluent water quality during the wastewater treatment process. The CBNLSMA model is divided into four stages: the CNN module for feature extraction and data filtering to expedite operations;the BNLSTM module for temporal data’s temporal information extraction;the AM module for model weight reassignment;and the TPE optimization algorithm for the CBNLSMA model’s hyperparameter search optimization. In comparison with other models (TPE-CNN-BNLSTM, TPE-BNLSTM-AM, TPE-CNN-AM, PSO-CBNLSTMA), the CBNLSMA model reduced the RMSE for effluent COD prediction by 25.4%, decreased the MAPE by 32.9%, and enhanced the R2 by 14.9%. For the effluent SS prediction, the CBNLSMA model reduced the RMSE by 26.4%, the MAPE by 21.0%, and improved the R2 by 35.7% compared to other models. The simulation results demonstrate that the proposed CBNLSMA model holds significant potential for real-time effluent quality monitoring, indicating its high potential for automated control in wastewater treatment processes.

关键词： Prediction model Soft measurement CNN-BNLSTM-AM model TPE optimization algorithm

GSM-MRF based classification approach for real-time moving object detection

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第2期9卷 250-255页

作者： xiang PAN yi-jun WU Institute of Information and Communication Engineering Zhejiang University Hangzhou 310027 China

Statistical and contextual information are typically used to detect moving regions in image sequences for a fixed *** this paper,we propose a fast and stable linear discriminant approach based on Gaussian Single Model(GSM)and Markov Random Field(MRF).The performance of GSM is analyzed first,and then two main improvements corresponding to the drawbacks of GSM are proposed:the latest filtered data based update scheme of the background model and the linear classification judgment rule based on spatial-temporal feature specified by *** results show that the proposed method runs more rapidly and accurately when compared with other methods.

关键词： Moving object detection Markov Random Field (MRF) Gaussian Single Model (GSM) Fisher Linear Discriminant Analysis (FLDA)

Interfaces engineering of heterostructured Ni Co P/Ni Fe LDH@CC for attaining high catalytic activity in long-lasting rechargeable Zn-air batteries

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Rare Metals 2024年第10期43卷 4961-4972页

作者： Xiao-Lin Hu Ji-Chuan Fan xiang Li Zhen-Kun Wu Yuan-yi Li Chao-he Xu School of Science Chongqing Key Laboratory of New Energy Storage Materials and DevicesChongqing University of TechnologyChongqing 400054China JINSHAN Science&Technology(Group)Co. Lid.Lhongqing 401120China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400044China College of Aerospace Engineering Chongqing UniversityChongqing 400044China

Zinc-air batteries(ZABs)offer tremendous potential in various industries and daily life due to their excellent energy density,safety and ***,the practical application of ZABs has been severely hindered by challenges such as high low round-trip efficiencies and overpotential,primarily attributed to the inherent sluggish kinetics in the oxygen evolution reaction(OER)of air *** address these issues effectively and economically,heterojunction engineering accompanied by interfacial chemistry emerges as an ideal approach to designing efficient OER ***,a novel heterogeneous interfacial chemical structure,namely NiCoP/NiFe LDH(layered double hydroxide),needle-like NiCoP and NiFe LDH nanosheets were assembled from cores and shells,***,the NiCoP/NiFe LDH-based ZABs have an exceptionally long cycle life of 238 h,far superior to Pt/C+Ir/C batteries(~97 h).Theoretical calculations and experimental results demonstrate that NiCoP/NiFe LDH possesses tunable interfacial chemistry,demonstrating significant electronic,coordination,geometric and synergistic *** enhancements dramatically improve the active site density,intrinsic activity and electrochemical durability of the *** summary,this work provides a solid foundation for the development of costeffective OER electrocatalysts for electrochemical energy devices.

关键词： Zinc-air batteries Oxygen evolution reaction Interface catalysis Coupling effects Theoretical simulation

经颈内动脉灌注血管生成拮抗剂TNP-470对VX2脑转移瘤的影响

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实用放射学杂志 2003年第7期19卷 577-579页

作者：魏光全宦怡张贵祥贺洪德杨勇赵海涛葛雅丽第四军医大学西京医院放射科上海市第一人民医院放射科第四军医大学西京医院放射科陕西西安710032

目的　观察经颈内动脉灌注血管生成拮抗剂TNP -4 70对VX2 脑转移瘤生物学行为的影响。方法　建立VX2 脑转移瘤模型 ,筛选脑转移瘤长至 3cm者 18只 ,经颈内动脉灌注不同剂量TNP -4 70治疗 ,1次 /d ,共 6d。应用增强MRI进行评估。肿瘤体... 详细信息

目的　观察经颈内动脉灌注血管生成拮抗剂TNP -4 70对VX2 脑转移瘤生物学行为的影响。方法　建立VX2 脑转移瘤模型 ,筛选脑转移瘤长至 3cm者 18只 ,经颈内动脉灌注不同剂量TNP -4 70治疗 ,1次 /d ,共 6d。应用增强MRI进行评估。肿瘤体积的变化以增强MRI上测定的肿瘤直径为观察指标。结果　在接种VX2 后 1周左右后所有动物模型均逐渐出现食欲下降 ,体重下降等现象。TNP -4 70治疗后治疗组症状缓解 ,而对照组的动物症状呈进行性加重。从MRI观察到 ,无论应用 10mg/kg或者 3 0mg/kg治疗 ,给药 4、6d后 ,治疗组肿瘤的直径均小于对照组（Ρ 0 .0 5 ）。结论　TNP -4 70能抑制VX2 脑转移瘤的生长

关键词：动物实验脑肿瘤,转移抗血管生成治疗