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Robust dynamic surface control of flexible joint robots using recurrent neural networks

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控制理论与应用（英文版） 2013年第2期11卷 222-229页

作者： zhiqiang miao Yaonan WANG College of Electrical and Information Engineering Hunan University

A robust neuro-adaptive controller for uncertain flexible joint robots is presented. This control scheme integrates H^infinity disturbance attenuation design and recurrent neural network adaptive control technique into the dy- namic surface control framework. Two recurrent neural networks are used to adaptively learn the uncertain functions in a flexible joint robot. Then, the effects of approximation error and filter error on the tracking performance are attenuated to a prescribed level by the embedded H-infinity controller, so that the desired H-infinity tracking performance can be achieved. Finally. simulation results verifv the effectiveness of the nronosed control scheme.

关键词： Dynamic surface control Flexible joint robots Robust H-infinity control Recurrent neural network

Elevational distribution of forests and its spatiotemporal dynamics in subtropical China from 2000 to 2019

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Science China Earth Sciences 2024年第8期67卷 2563-2582页

作者： Zhencan ZHENG Liuwen ZHUANG Guofang miao Han LIU zhiqiang CHENG Wenyu LI Rong SHANG Peng GONG Jing Ming CHEN Institute of Geography Fujian Normal University Key Laboratory of Humid Subtropical Eco-Geographical Process (Ministry of Education) Fujian Normal University School of Geographical Sciences Fujian Normal University National Land Consolidation Center Ministry of Natural Resources Key Laboratory of Land Consolidation and Rehabilitation Ministry of Natural Resources Key Laboratory of Digital Mapping and Land Information Application Ministry of Natural Resources Department of Geography & Planning University of Toronto Department of Geography The University of Hong Kong

The subtropical region of China possesses abundant forest resources and features a mountainous *** the implementation of policies such as natural forest protection,the Grain for Green Project,and other initiatives since the beginning of the 21st century,coupled with climate change,the forest resources in this region have undergone significant changes compared to historical *** addition,forest resources distributing mainly in mountainous areas also implies that these changes may vary significantly with *** explore the spatiotemporal dynamics of forest distribution in subtropical China since 2000,especially the trend of changes with elevation,we analyzed the data from two land cover products focusing on forest cover and forest *** used a hierarchical approach,in which coarse-classification forest cover data with relatively small uncertainties impose constraints on forest type data with larger uncertainties,to achieve a reasonable balance between obtaining more details and reducing data *** first divided the forest cover data into‘unchanged'and‘changed'*** the constraints by the forest cover results,we further analyzed the‘unchanged'and‘changed'forest *** results indicated that,since the implementation of ecological engineering and management policies,54%of the area in the subtropical region had maintained unchanged forest cover attributes over the past 20 years,which implied the good state of ecological *** results also showed that dynamic conversions existed in the long term between forests and lands for essential production needs like *** elevational variations of forest cover suggested that the dominant changes came from the conversion between forests and croplands in low-elevation regions below 700 m,the conversion between forests and shrublands in mid-elevation regions of 700–1500 m,and the conversion between forests and grasslands in high-elevation regions above 2000 *** the regio

关键词： Subtropical China Land cover Forest cover Forest type Elevational distribution

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日粮添加益生菌改善乳鸽肠道健康和生产性能

山西农业大学学报（自然科学版） 2024年第2期44卷 71-79页

作者：董元洋韩鹏敏郑钰崎苗志强韩苗苗宋献艺张俊珍麻慧王政李慧锋李建慧山西农业大学动物科学学院山西晋中030801 中国农业科学院北京畜牧兽医研究所北京100193 山西农业大学生命科学学院山西晋中030801

[目的]本文旨在研究在日粮中添加屎肠球菌和枯草芽孢杆菌对乳鸽生长性能的改善效果,及是否通过调节肠道形态、消化酶活性及肠道微生物区系,发挥促生产作用。[方法]试验选取240只12日龄、体重接近的健康白羽王鸽,随机分成4组,分别为对照... 详细信息

[目的]本文旨在研究在日粮中添加屎肠球菌和枯草芽孢杆菌对乳鸽生长性能的改善效果,及是否通过调节肠道形态、消化酶活性及肠道微生物区系,发挥促生产作用。[方法]试验选取240只12日龄、体重接近的健康白羽王鸽,随机分成4组,分别为对照组、屎肠球菌组、枯草芽孢杆菌组、屎肠球菌与枯草芽孢杆菌混合添加组。于试验第16天(28日龄)测定生产性能并进行屠宰采样,测定十二指肠、空肠、回肠肠道形态,十二指肠内容物消化酶活性和结直肠微生物区系等指标。[结果]与对照组相比,屎肠球菌处理组显著提高12~28 d龄平均日增重。与对照组相比,屎肠球菌处理可显著提高十二指肠胰蛋白酶活性,枯草芽孢杆菌及混合处理添加可显著提高十二指肠中淀粉酶活性(P<0.05)。益生菌单独或混合添加处理组乳鸽的十二指肠、空肠、回肠绒毛高度显著升高,均显著提高空肠、回肠的绒毛高度与隐窝深度比值(P<0.05);16S rRNA分析结直肠微生物区系结果表明,单独或混合添加屎肠球菌、枯草芽孢杆菌可提高结直肠奇异菌属(Atopobium)、分节丝状菌(Candidatus Arthromitus)、芽孢杆菌(Bacillus)丰度,以上益生菌具有肠道改善功能。[结论]屎肠球菌和枯草芽孢杆菌可改善乳鸽肠道形态,提高消化酶活性,增加肠道有益菌数量,进而促进乳鸽生长性能,具有良好的生产应用潜力。

关键词：益生菌乳鸽肠道健康生产性能

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Interaction of yttrium barrier and calcium-rich phase on production and properties of WC precursor powders and alloys

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Journal of Rare Earths 2024年第1期42卷 228-236,I0008页

作者： Wen He Dunqiang Tan zhiqiang Yi zhiqiang Liu School of Materials Science and Engineering Nanchang UniversityNanchang330031China Instrumental Analysis Center of Nanchang Hangkong University Nanchang330063China

In order to reduce or eliminate the adverse effects of calcium impurity,the interaction of Ca and rare earth Y co-doping on the preparation of WC-Co cemented carbides was investigated.X-ray diffraction,scanning electron microscopy and transmission electron microscopy were employed to analyze the phase compositions,particle sizes and morphologies of them,*** results show that the second type of"yttrium barrier effect"is observed and the adverse influence of Ca-rich phase on tungsten powder can be eliminated by *** flexural strength and fracture toughness of YG6-0.01%Ca+0.09%Y alloy are 2199.5 MPa and 11.49 MPa·m^(1/2),showing improvement of 6.5% and 2.7% compared to YG6 alloy,*** evolutions of Ca-rich phase and Y-rich phase at the every alloy preparation stage of WO_(3),W,WC and cemented carbides are ***,the strengthening mechanism of WC-Co cemented carbide with co-addition of Ca and Y is proposed.

关键词： Yttrium barrier effect Ca-rich phase WC-Co cemented Carbide Microstructures Mechanisms Rare earths

Semi-analytical Solutions for Wellbores with Graded Skin Zones in Poroelastic Media

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Acta Mechanica Solida Sinica 2024年第3期37卷 385-395页

作者： zhiqiang Fan Zhihe Jin School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi’an710072China Department of Mechanical Engineering University of MaineOronoME04469USA

In analyzing the complex interaction between the wellbore and the reservoir formation,the hydromechanical properties of the region proximal to the wellbore,referred to as the“wellbore skin zone”,play a pivotal role in determining flow dynamics and the resulting formation *** models of the wellbore skin zone generally assume a constant permeability throughout,resulting in a sharp permeability discontinuity at the skin-reservoir *** paper introduces a model for a wellbore with a continuously graded skin zone of finite thickness within a poroelastic *** solutions are derived using the Laplace transform method,addressing both positive and negative skin *** results are presented to illustrate the effects of graded permeability/skin zone thickness on pore pressures and stresses around a *** results highlight a distinct divergence in stress and pore pressure fields when comparing wellbores with negative skin zones to those with positive skin zones or no skin at all.

关键词： Poroelastic Graded permeability Analytical solution Wellbore Skin zone

多信使时代下中子星状态方程的贝叶斯模型选择

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原子能科学技术 2023年第4期57卷 784-790页

作者：芮星宇缪志强夏铖君扬州大学物理科学与技术学院江苏扬州225009 厦门大学天文系福建厦门361005

当前中子星的观测为其状态方程提供了严格的约束条件。基于双中子星并合事件GW170817对潮汐形变的约束,以及NICER合作组对PSR J0030+0451和PSR J0740+6620的质量和半径的测量,本文对CompOSE数据库中基于相对论平均场模型统一得到的16组... 详细信息

当前中子星的观测为其状态方程提供了严格的约束条件。基于双中子星并合事件GW170817对潮汐形变的约束,以及NICER合作组对PSR J0030+0451和PSR J0740+6620的质量和半径的测量,本文对CompOSE数据库中基于相对论平均场模型统一得到的16组中子星状态方程开展了贝叶斯模型选择。发现最理想的物态模型是DD2,它预测1.4倍太阳质量中子星的半径为13.19 km,潮汐形变为687。在此基础之上,进一步筛选出最符合观测的物态模型依次为DD2、TW99、DD-LZ1、DD-ME2、TM1e、FSU2H、DDME-X、PKDD、FSU2R和MTVTC。

关键词：核物质状态方程贝叶斯模型选择多信使时代

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Key-Part Attention Retrieval for Robotic Object Recognition

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Tsinghua Science and Technology 2024年第3期29卷 644-655页

作者： Jierui Liu zhiqiang Cao Yingbo Tang State KeyLaboratory of Multimodal Artificial Intelligence Systems Institute of AutomationChinese Academy of SciencesBeijing100190China School of Artificial Intelligence University of Chinese Academy of SciencesBeijing 100049China

The ability to recognize novel objects with a few visual samples is critical in the robotic *** methods mainly concern the recognition of inter-category objects,however,the object recognition fromdifferent sub-classes within the same category remains challenging due to their similar *** thispaper,we propose a key-part attention retrieval solution to distinguish novel objects of different sub-classesaccording to a few samples without ***,an object encoder,including convolutional neuralnetwork with attention and key-part aggregation,is designed to generate object attention map and extract theobject-level embedding,where object attention map from the middle stage of the backbone is used to guide thekey-part ***,to overcome the non-differentiability drawback of key-part attention,the objectencoder is trained in a two-step scheme,and a more stable object-level embedding is *** this basis,the potential objects are located from a scene image by mining connected domains of the attention *** the embedding of each potential object and embeddings from support data,the recognition of thepotential objects is *** effectiveness of the proposed method is verified by experiments.

关键词： key-part attention retrieval robotic object recognition

A Review on Flow Boiling of the Fluid with Lower Boiling Point in Micro-Channels

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Journal of Thermal Science 2024年第1期33卷 1-17页

作者： ZHANG zhiqiang JIA Li DANG Chao Beijing Key Laboratory of Flow and Heat Transfer of Phase Changing in Micro and Small Scale School of MechanicalElectronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China

With the advancement of micro machining technology,the high-heat-flux removal from miniature electronic devices and components has become an attractive *** boiling in micro-channels is an optimal form of heat transfer and has been widely employed in high-heat-flux cooling *** comprehensively-reviewed article focused on the available recent literatures of experimental investigation regarding the flow boiling heat transfer and unstable behaviors of the fluid with lower boiling point in *** thermal-fluid characteristics and potential heat transfer mechanisms of low-boiling-point fluids flow boiling in different narrow passages were summarized and *** literatures regarding the pressure drop and occurrence of the unstable phenomena existing in two-phase flow boiling process were also *** emphasis was given to the heat transfer enhancement methods as well as instability elimination,and various methods such as modification of surface and channel flow geometries were *** future researches in the field of micro-scale flow boiling were suggested.

关键词： flow boiling lower boiling point fluids mini/micro-channels instabilities enhancement suppression

Operational optimization of copper flotation process based on the weighted Gaussian process regression and index-oriented adaptive differential evolution algorithm

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Chinese Journal of Chemical Engineering 2024年第2期66卷 167-179页

作者： zhiqiang Wang Dakuo He Haotian Nie College of Information Science and Engineering Northeastern UniversityShenyang 110004China State Key Laboratory of Synthetical Automation for Process Industries Northeastern UniversityShenyang 110004China

Concentrate copper grade(CCG)is one of the important production indicators of copper flotation processes,and keeping the CCG at the set value is of great significance to the economic benefit of copper flotation industrial *** paper addresses the fluctuation problem of CCG through an operational optimization ***,a density-based affinity propagationalgorithm is proposed so that more ideal working condition categories can be obtained for the complex raw ore ***,a Bayesian network(BN)is applied to explore the relationship between the operational variables and the *** on the analysis results of BN,a weighted Gaussian process regression model is constructed to predict the CCG that a higher prediction accuracy can be *** ensure the predicted CCG is close to the set value with a smaller magnitude of the operation adjustments and a smaller uncertainty of the prediction results,an index-oriented adaptive differential evolution(IOADE)algorithm is proposed,and the convergence performance of IOADE is superior to the traditional differential evolution and adaptive differential evolution ***,the effectiveness and feasibility of the proposed methods are verified by the experiments on a copper flotation industrial process.

关键词： Weighted Gaussian process regression Index-oriented adaptive differential evolution Operational optimization Copper flotation process