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Effect of droplet characteristics on liquid-phase distribution in spray zone of internal mixing air-mist nozzle

China Foundry 2024年第2期21卷 185-196页

作者： wei-li Wu Chang-gui Cheng Yang Li shi-fa wei De-li Chen The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081China Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan 430081China Technology Center Fushun Special Steel Co.Ltd.Fushun 113001LiaoningChina

In continuous casting production,droplet characteristics are important parameters for evaluating the nozzle atomization quality,and have a significant impact on the secondary cooling effect and the slab *** order to study the behavior of atomized droplets after reaching the slab surface and to optimize the spray cooling effect,the influence of droplet diameter and droplet velocity on the migration behavior of droplets in the secondary cooling zone was analyzed by FLUENT *** show that the droplets in the spray zone and on the slab surface are mainly concentrated in the center,thus,the liquid volume fraction in the center is higher than that of either *** the droplet diameter increases,the region of high liquid volume fraction on the slab surface becomes wider,and the liquid phase distribution in the slab width direction becomes *** increasing the droplet velocity at the nozzle exit has little effect on droplet diffusion in the spray zone,the distribution becomes more uneven due to more liquid reaches the slab surface per unit time.A prediction formula of the maximum water flow rate on the slab surface for specific droplet characteristics was proposed based on dimensionless analysis and validated by simulated data.A nozzle spacing of 210 mm was recommended under the working conditions in this study,which ensures effective coverage of the spray water over the slab surface and enhances the distribution uniformity of water flow rate in the transverse direction.

关键词： continuous casting secondary cooling zone internal mixing air-mist nozzle droplet characteristics liquid phase distribution water flow rate

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Two-dimensional bimetallic coordination polymers as bifunctional evolved electrocatalysts for enhanced oxygen evolution reaction and urea oxidation reaction

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Journal of Energy Chemistry 2021年第12期30卷 230-238,I0005页

作者： Qiang Li Lele Lu Jingwei Liu wei shi Peng Cheng Key Laboratory of Advanced Energy Materials Chemistry(MOE) College of ChemistryNankai UniversityTianjin 300071China

Two-dimensional coordination polymers(CPs) have aroused tremendous interest as electrocatalysts because the catalytic performance could be fine-tuned by their well-designed coordination layers with highly accessible and active metal ***,it remains great challenge for CP-based catalysts to be utilized for electrocatalytic oxidation reactions due to their inefficient activities and low catalytic ***,we applied a mixed-metal strategy to fabricate two-dimensional Co_xNi_(1-x)-CPs with dual active sites for electrocatalytic water and urea *** metal ratio regulation in the twodimensional layer,an optimized Co_(2/3)Ni_(1/3)-CP exhibits a water oxidation performance with an overpotential of 325 mV at a current density of 10 mA cm^(-2) and a Tafel slope of 86 mV dec^(-1) in alkaline solution for oxygen evolution ***,a lower potential than that of commercial RuO_(2) is observed over20 mA cm^(-2).Co_(2/3)Ni_(1/3)-CP also displays a potential of 1.381 V at 10 mA cm^(-2) for urea oxidation reaction and a Tafel slope of 124 mV dec^(-1).This mixed-metal strategy to maximize synergistic effect of different metal centers may ultimately lead to promising electrocatalysts for small molecule oxidation reaction.

关键词： Coordination Polymers Electrocatalysis Oxygen Evolution Reaction Urea Oxidation Reaction

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Weakly supervised action anticipation without object annotations

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Frontiers of Computer Science 2023年第2期17卷 101-110页

作者： Yi ZHONG Jia-Hui PAN Haoxin LI wei-shi ZHENG School of Computer Science and Engineering Sun Yat-sen UniversityGuangzhou 510006China Key Laboratory of Machine Intelligence and Advanced Computing Ministry of EducationGuangzhou 510006China

Anticipating future actions without observing any partial videos of future actions plays an important role in action prediction and is also a challenging *** obtain abundant information for action anticipation,some methods integrate multimodal contexts,including scene object ***,extensively labelling each frame in video datasets requires considerable *** this paper,we develop a weakly supervised method that integrates global motion and local finegrained features from current action videos to predict next action label without the need for specific scene context ***,we extract diverse types of local features with weakly supervised learning,including object appearance and human pose representations without ground ***,we construct a graph convolutional network for exploiting the inherent relationships of humans and objects under present *** evaluate the proposed model on two datasets,the MPII-Cooking dataset and the EPIC-Kitchens dataset,and we demonstrate the generalizability and effectiveness of our approach for action anticipation.

关键词： action anticipation weakly supervised learning relation modelling graph convolutional network

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Mechanisms of Salt Tolerance in Transgenic Arabidopsis thaliana Carrying a Peroxisomal Ascorbate Peroxidase Gene from Barley

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Pedosphere 2008年第4期18卷 486-495页

作者： XU wei-Feng shi wei-Ming A. UEDA T. TAKABE State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 （China）. Graduate School of the Chinese Academy of Sciences Beijing 100049 （China） Graduate School of Bioagricultural Sciences Nagoya University Nagoya 464-8601 （Japan

Ascorbate peroxidases （APX）, localized in the cytosol, peroxisome, mitochondria, and chloroplasts of plant cells, catalyze the reduction of H2O2 to water by using ascorbic acid as the specific electron donor. To determine the role of peroxisomal type ascorbate peroxidase （pAPX）, an antioxidant enzyme, in protection against salt-induced oxidative stress, transgenic Arabidopsis thaliana plant carrying a pAPX gene （HvAPX1） from barley （Hordeum vulgate L.） was analyzed. The transgenic line pAPX3 was found to be more tolerant to salt stress than the wild type. Irrespective of salt stress, there were no significant differences in Na^＋, K^＋, Ca^2＋, and Mg^2＋ contents and the ratio of K^＋ to Na^＋ between pAPX3 and the wild type. Clearly, the salt tolerance in pAPX3 was not due to the maintenance and reestablishment of cellular ion homeostasis. However, the degree of H2O2 and lipid peroxidation （measured as the levels of malondialdehyde） accumulation under salt stress was higher in the wild type than in pAPX3. The mechanism of salt tolerance in transgenic pAPX3 can thus be explained by reduction of oxidative stress injury. Under all conditions tested, activities of superoxide, glutathione reductase, and catalase were not significantly different between pAPX3 and the wild type. In contrast, the activity of APX was significantly higher in the transgenic plant than in wild type under salt stress. These results suggested that in higher plants, HvAPX1 played an important role in salt tolerance and was a candidate gene for developing salttolerant crop plants.

关键词： ascorbate peroxidase oxidative stress peroxisome soil salinity transgenic Arabidopsis thaliana

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Hydrogen Peroxide in Plants:a Versatile Molecule of the Reactive Oxygen Species Network

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Journal of Integrative Plant Biology 2008年第1期50卷 2-18页

作者： Li-Juan Quan Bo Zhang wei-wei shi Hong-Yu Li MOE Key Laboratory of Arid and Grassland Ecology School of Life Sciences Lanzhou University Lanzhou 730000 China

Plants often face the challenge of severe environmental conditions, which include various biotic and abiotic stresses that exert adverse effects on plant growth and development. During evolution, plants have evolved complex regulatory mechanisms to adapt to various environmental stressors. One of the consequences of stress is an increase in the cellular concentration of reactive oxygen species （ROS）, which are subsequently converted to hydrogen peroxide （H2O2）. Even under normal conditions, higher plants produce ROS during metabolic processes. Excess concentrations of ROS result in oxidative damage to or the apoptotic death of cells. Development of an antioxidant defense system in plants protects them against oxidative stress damage. These ROS and, more particularly, H2O2, play versatile roles in normal plant physiological processes and in resistance to stresses. Recently, H2O2 has been regarded as a signaling molecule and regulator of the expression of some genes in cells. This review describes various aspects of H2O2 function, generation and scavenging, gene regulation and cross-links with other physiological molecules during plant growth, development and resistance responses.

关键词： antioxidant system gene regulation hydrogen peroxide (H2O2) reactive oxygen species (ROS) signaling molecule.

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探讨师伟教授治疗子宫腺肌病的用药规律信息学研究

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中药药理与临床 2024年第8期40卷 103-107,35页

作者：刘洋师伟山东中医药大学第一临床医学院济南250014 山东中医药大学附属医院妇科济南250014

目的:基于数据挖掘探讨师伟教授治疗子宫腺肌病(Adenmyosis,AM)的用药规律。方法:收集2020年5月1日-2023年5月31日就诊于山东中医药大学附属医院师伟教授专家门诊的子宫腺肌病患者病案信息,用Excel软件建立处方数据库,采用SPSS Modeler1... 详细信息

目的:基于数据挖掘探讨师伟教授治疗子宫腺肌病(Adenmyosis,AM)的用药规律。方法:收集2020年5月1日-2023年5月31日就诊于山东中医药大学附属医院师伟教授专家门诊的子宫腺肌病患者病案信息,用Excel软件建立处方数据库,采用SPSS Modeler18.0、SPSS Statistics 25.0软件对中药处方中的药物分别进行药物的复杂网络分析、二项、三项关联分析、系统聚类。结果:纳入254例子宫腺肌病患者临床病案处方信息,收集有效处方768首,涉及药物174味,用药总频次15827次。统计分析得出,师伟教授在治疗子宫腺肌病的组方中使用频次最多的药物是甘草、黄芪、赤芍、茯苓、皂角刺、重楼、桂枝、桃仁、没药、牡丹皮;“四气”使用频次较多的是寒、温、平性,“五味”使用频次最多的是甘、苦、辛味,“归经”使用频次最多的是肝经、心经、脾经,中药功效使用频次最多的是补虚药、活血化瘀药。复杂网络核心处方主要由桂枝茯苓丸合黄芪建中汤合没竭散化裁组成,高频药物系统聚类分析得到5个药物聚类组合。结论:师伟教授认为AM病机是阳虚血瘀为本,病位在冲任、胞宫,变化在气血,表现为痛证与血证。在治疗AM时,师伟教授遵循“衰其大半而止”的原则,治法重在平心、调肝、健脾,燮理冲任气血,恢复脏腑功能;用药寒温平调,攻邪不忘扶正,以益气活血、祛瘀消癥为主;临证遣方擅于化裁经典方剂,方简效宏。治疗时谨守病机,审证求因,分期施治。

关键词：数据挖掘子宫腺肌病用药规律师伟教授

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An approach for detecting LDoS attack based on cloud model

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Frontiers of Computer Science 2022年第6期16卷 123-134页

作者： wei shi Dan TANG Sijia ZHAN Zheng QIN Xiyin WANG College of Computer Science and Electronic Engineering Hunan UniversityChangsha410082China

Cybersecurity has always been the focus of Internet *** LDoS attack is an intelligent type of DoS attack,which reduces the quality of network service by periodically sending high-speed but short-pulse attack *** of its concealment and low average rate,the traditional DoS attack detection methods are challenging to be *** existing LDoS attack detection methods generally have the problems of high FPR and FNR.A cloud model-based LDoS attack detection method is proposed,and a classifier based on SVM is used to train and classify the feature *** detection method is verified and tested in the NS2 simulation platform and Test-bed network *** with the existing research results,the proposed method requires fewer samples,and it has lower FPR and FNR.

关键词： cybersecurity LDoS attack cloud model SVM

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A novel variable topology design for a multi-flexible ejection mechanism

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Defence Technology（防务技术） 2020年第2期16卷 432-438页

作者： Hao Liu Jun Zhou Zong-lai Mo shi-wei Zhang School of Astronautics Northwestern Polytechnical UniversityXi'an710072China School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094China Luoyang Opto-Electro Technology Development Center 471009China

The airborne missile launch mechanism often subjects to significant deformations induced by the large ejection force during high-speed actuations in missile ejection process,leading to a substantial deviation of separation parameters from designed values that threats safety of the *** study proposes a novel variable topology design for launch mechanism,achieved via a Prsmatic-Revolute-Revolute pair(PR-R)motion formed by the structural gap with a specific *** enables launch mechanism variability during missile ejection process and optimizes the ejection force given by the front and back ejection arms,and greatly optimizes the separation parameters during missile *** kinetics simulation analysis is conducted under working conditions of the original ejection mechanism and the novel mechanism with variable topology design,*** results show that the novel variable topology design is more befitting for the launch process in terms of system safety and controllability,effectively improving the separation posture,restraining the flexible effect of the mechanism,and fulfilling the effectiveness of the design value of multi-rigid body.

关键词： Variable topology Gap dynamics Multi-flexible body Flexible control Ejection mechanism

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Yaw stability control using the fuzzy PID controller for active front steering

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High Technology Letters 2010年第1期16卷 94-98页

作者：李强 shi Guobiao wei Jie School of Mechanical and Vehicular Engineering Beijing Institute of Technology Beijing 100081 P.R. China

In order to improve the yaw stability of the vehicle with active front steering system, an adaptive PID-type fuzzy control scheme is designed to make the yaw rate tracking the desired values as close as possible. A 2-DOF vehicle model with active front steering is built firstly, and then the fuzzy PID controller is designed in detail. The simulation investigations of the yaw stability with different steering ma- neuvers are performed. The simulation results show the effectiveness of the fuzzy PID controller for improving the vehicle＇s yaw stability.

关键词： vehicle active front steering (AFS) yaw stability fuzzy PID control

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Object recognition and pose estimation using appearance manifolds

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Advances in Manufacturing 2013年第3期1卷 258-264页

作者： Zhong-Hua Hao shi-wei Ma School of Mechatromc Engineering and Automation Key Laboratory of Power Station Automation Technology Shanghai University

Conventionally, image object recognition and pose estimation are two independent components in machine vision. This paper presented a simple but effective method KNNSNG, which tightly couples these two com ponents within a single algorithm framework. The basic idea of this method came from the bionic pattern recog nition and the manifold ways of perception. Firstly, the shortest neighborhood graphs （SNG） are established for each registered object. SNG can be regarded as a covering and triangulation for a hypersurface on which the training data are distributed. Then for recognition task, the deter mined test image lies on which SNG by employing the parameter ＂k＂, which can be calculated adaptively. Finally, the local linear approximation method is adopted to build a local map between highdimensional image space and lowdimensional manifold for pose estimation. The projective coordinates on manifold can depict the pose of object. Experiment results manifested the effectiveness of the method.

关键词： Object recognition Pose estimation -Manifold

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