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Kinematic calibration method with high measurement efficiency and robust identification for hybrid machine tools

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Chinese Journal of Aeronautics 2024年第3期37卷 468-482页

作者： Liping WANG Mengyu LI Guang YU Weitao LI Xiangyu KONG State key laboratory of Tribology Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China Beijing key laboratory of Precision/Ultra-precision Manufacturing Equipment and control Beijing 100084China

Geometric error is the main factor affecting the machining accuracy of hybrid machine *** calibration is an effective way to improve the geometric accuracy of hybrid machine *** necessity to measure both position and orientation at each pose,as well as the instability of identification in case of incomplete measurements,severely affects the application of traditional calibration *** this study,a kinematic calibration method with high measurement efficiency and robust identification is proposed to improve the kinematic accuracy of a five-axis hybrid machine ***,the configuration is introduced,and an error model is ***,by investigating the mechanism error characteristics,a measurement scheme that only requires tool centre point position error measurement and one alignment operation is ***,by analysing the effects of unmeasured degrees of freedom(DOFs)on other DOFs,an improved nonlinear least squares method based on virtual measurement values is proposed to achieve stable parameter identification in case of incomplete measurement,without introducing additional ***,the proposed calibration method is verified through simulations and *** proposed method can efficiently accomplish the kinematic calibration of the hybrid machine *** accuracy of the hybrid machine tool is significantly improved after calibration,satisfying actual aerospace machining requirements.

关键词： Hybrid machine tool Calibration Measurement scheme Improved nonlinear least squares method Virtual measurement values

Highly active copper-intercalated weakly crystallized δ-MnO_(2) for low-temperature oxidation of CO in dry and humid air

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Frontiers of Environmental Science & Engineering 2024年第5期18卷 127-136页

作者： Hao Zhang Huinan Li Pengyi Zhang Tingxia Hu Xianjie Wang State key Joint laboratory of Environment Simulation and Pollution control School of EnvironmentTsinghua UniversityBeijing100084China Beijing key laboratory for Indoor Air Quality Evaluation and control Beijing100084China Midea Corporate Research Center Foshan528311China

Copper intercalated birnessite MnO_(2)(δ-MnO_(2))with weak crystallinity and high specific surface area(421 m^(2)/g)was synthesized by a one-pot redox method and investigated for low-temperature CO *** molar ratio of Cu/Mn was as high as 0.37,which greatly weakened the Mn-O bond and created a lot of low-temperature active oxygen *** situ DRIFTS revealed strong bonding of copper ions with ***-synthesized MnO_(2)-150Cu achieved 100%conversion of 250 ppm CO in normal air(3.1 ppm H_(2)O)even at−10°C under the weight-hourly space velocity(WHSV)of 150 L/(g·h).In addition,it showed high oxygen storage capacity to oxidize CO in inert *** the concurrent moisture in air significantly inhibited CO adsorption and its conversion at ambient temperature,MnO_(2)-150Cu could stably convert CO in 1.3%moisture air at 70°C owing to its great low-temperature activity and reduced competitive adsorption of water with increased *** study discovers the excellent low-temperature activity of weakly crystallized δ-MnO_(2) induced by high content intercalated copper ions.

关键词： CO oxidation Birnessite Interlayer copper Low-temperature Oxygen storage capacity

Biomineralization and mineralization using microfluidics:A comparison study

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 661-669页

作者： Yang Xiao Xiang He Guoliang Ma Chang Zhao Jian Chu Hanlong Liu key laboratory of New Technology for Construction of Cities in Mountain Area Chongqing UniversityChongqing400045China State key laboratory of coal Mine Disaster Dynamics and control Chongqing UniversityChongqing400045China School of Civil Engineering Chongqing UniversityChongqing400045China School of Civil and Environmental Engineering Nanyang Technological UniversitySingapore

Biomineralization through microbial process has attracted great attention in the field of geotechnical engineering due to its ability to bind granular materials,clog pores,and seal *** minerals formed by biomineralization are generally the same as that by mineralization,their mechanical behaviors show a significant *** study aims to figure out the differences between biomineralization and mineralization processes by visualizing and tracking the formation of minerals using *** biomineralization and mineralization processes occurred in the Y-shaped sandcontaining microchip that mimics the underground sand *** from different areas in the reaction microchannel of microchips were captured to directly compare the distribution of *** size and numbers from different reaction times were measured to quantify the differences between biomineralization and mineralization processes in terms of crystal *** showed that the crystals were precipitated in a faster and more uncontrollable manner in the mineralization process than that in the biomineralization process,given that those two processes presented similar precipitation *** addition,a more heterogeneous distribution of crystals was observed during the biomineralization *** precipitation behaviors were further explained by the classical nucleation crystal growth *** present microfluidic tests could advance the understanding of biomineralization and provide new insight into the optimization of biocementation technology.

关键词： Microbially induced carbonate precipitation (MICP) Biocementation Crystal Calcium carbonate Nucleation

A vibration isolator with a controllable quasi-zero stiffness region based on nonlinear force design

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Applied Mathematics and Mechanics(English Edition) 2024年第8期45卷 1279-1294页

作者： Xinyu LIAN Bing LIU Huaxia DENG Xinglong GONG CAS key laboratory of Mechanical Behavior and Design of Materials Department of Modern MechanicsUniversity of Science and Technology of ChinaHefei 230027China State key laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China State key laboratory of fire Science University of Science and Technology of ChinaHefei 230026China

To achieve stability optimization in low-frequency vibration control for precision instruments,this paper presents a quasi-zero stiffness(QZS)vibration isolator with adjustable nonlinear ***,the stress-magnetism coupling model is established through meticulous theoretical *** controllable QZS interval is constructed via parameter design and magnetic control,effectively segregating the high static stiffness bearing section from the QZS vibration isolation ***,a displacement control scheme utilizing a magnetic force is proposed to regulate entry into the QZS working range for the vibration isolation *** results demonstrate that the operation within this QZS region reduces the peak-to-peak acceleration signal by approximately 66.7%compared with the operation outside this region,thereby significantly improving the low frequency performance of the QZS vibration isolator.

关键词： low frequency nonlinear vibration isolator quasi-zero stiffness(QzS)

Novel process for facile preparation of mesoporous silica-based materials with controllable pore structure from coal fly ash Author links open overlay panel

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Particuology 2024年第8期91卷 128-137页

作者： Jian-ming Gao Zhen Li Shujia Ma Yuanyuan Zhang Fangqin Cheng Institute of Resources and Environment Engineering State Environmental Protection Key Laboratory of Efficient Utilization Technology of Coal Waste ResourcesShanxi Collaborative Innovation Center of High Value-added Utilization of Coal-related WastesShanxi UniversityTaiyuan 030006China

Extraction of silica from fly ash to produce mesoporous silica materials is one of the most important utilization *** silica could not be synthesized on a large-scale by conventional sol-gel *** this paper,facile preparation of mesoporous silica with controllable pore structure from fly ash by the template-free process via two steps of mineral phase transformation and selective acid etching was *** influence of crystalline structure and acid etching degree on structure of as-synthesized mesoporous silica materials was revealed,as well as mechanism of crystalline structure transformation and pore structure *** results show that mullite and quartz could be transformed into acid-soluble kaliophilite when fly ash reacted with K_(2)CO_(3)at temperature of 800-1100℃.The hexagonal kaliophilite would be transformed into orthorhombic KAlSiO_(4)-O1 phase when the temperature is controlled at 1100℃.Mesoporous silica with specific surface area of 475.93 m^(2)/g and 642.57 m^(2)/g could be synthesized from activated fly ash with kaliophilite and KAlSiO_(4)-O1 phase crystalline *** controlling the degree of acid etching,mesoporous silica materials with different pore structures can be *** paper provides a cost-effective and large-scale process for the preparation of mesoporous silica materials with controllable pore structure from solid waste fly ash.

关键词： Fly ash Mesoporous silica Crystal transformation Acid etching controllable pore structure

Variation in Bombyx mori immune response against fungal pathogen Beauveria bassiana with variability in cell wallβ-1,3-glucan

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Insect Science 2024年第1期31卷 211-224页

作者： Yulong Wang Zhen Liu Xuebing Yin Shihong Liu Kai Wang Rongjie Wan Haoran Chen Xinyang Li Bo Huang Anhui Provincial key laboratory of Microbial Pest control Anhui Agricultural UniversityHefeiChina

Entomopathogenic fungi are protected by a cell wall with dynamic structure for adapting to various environmental conditions.β-1,3-Glucan recognition proteins activate the innate immune system of insects by recognizing surface molecules of ***,the associations between pathogenicity and the different components of entomopathogenic fungal cell walls remain *** Beauveria bassiana strains were selected that have significantly differing virulence against Bombyx *** molecular mechanisms underlying the immune response in *** were investigated using RNA sequencing,which revealed differences in the immune response to different *** strains at 12 h *** assays revealed thatβ-1,3-glucan content had an opposite trend to that of fungal virulence.β-1,3-Glucan injection upregulated BmβGRP4 expression and significantly reduced the virulence of the high-virulence strain but not that of the medium-virulence or low-virulence ***βGRP4 silencing in *** with RNA interference resulted in the opposite virulence pattern,indicating that the virulence of *** was affected by the cell walls’content ofβ-1,3-glucan,which could be recognized by Bmβ***,interference with the gene CnA(calcineurin catalytic A subunit)involved inβ-1,3-glucan synthesis eliminated differences in virulence between *** *** results indicate that strains of a single species of pathogenic fungi that have differing cell wall components are recognized differently by the innate immune system of ***.

关键词： ombyx mori BmβGRP4 innate immunity insect fungal pathogen virulence

Evolution of soil DOM during thermal remediation below 100℃:concentration,spectral characteristics and complexation ability

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Frontiers of Environmental Science & Engineering 2024年第8期18卷 31-41页

作者： Wan Huang Ziren Wan Di Zheng Lifeng Cao Guanghe Li Fang Zhang State key Joint laboratory of Environment Simulation and Pollution control State Environment Protection Key Laboratory of Microorganism Application and Risk ControlSchool of EnvironmentTsinghua UniversityBeijing 100084China National Engineering laboratory for Site Remediation Technologies Beijing 100015China

The impact of thermal remediation on soil function has drawn increasing *** far,as the most active fraction of soil organic matter,the evolution of dissolved organic matter(DOM)during the thermal remediation lacks in-depth investigation,especially for the temperatures value below 100℃.In this study,a series of soil thermal treatment experiments was conducted at 30,60,and 90℃ during a 90-d period,where soil DOM concentration increased with heating temperature and *** molecular weight,functional groups content and aromaticity of DOM all decreased during the thermal *** excitation-emission matrices(EEM)results suggested that humic acid-like substances transformed into fulvic acid-like substances(FIII/FV increased from 0.27 to 0.44)during the heating process,and five DOM components were further identified by *** change of DOM structures and components indicated the decline of DOM stability and hydrophilicity,and can potentially change the bioavailability and *** temperature also resulted in the decline of DOM complexation ability,which may be caused by the loss of binding sites due to the decrease of polar function groups,aromatic structures and hydrophilic *** study provides valuable information about the evolution of DOM during thermal remediation,which would potentially change the fate of metal ions and the effectiveness of the post-treatment technologies in the treated region.

关键词： Thermal remediation below 100℃ Heating temperature Soil DOM concentration DOM spectral characteristics Excitation-emission matrices(EEM) Complexation ability

Enhancement of ionic conductivity and fracture toughness by infiltrating porous Li_(0.33)La_(0.56)TiO_(3) pellets

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Journal of Rare Earths 2024年第2期42卷 392-398,I0006页

作者： Xiaojuan Lu Mingyang Duan Jingyu Xiang Yuning Liang Songtao Liu Hebei key Lab of Power Plant Flue gas Multi-Pollutants control Department of Environmental Science and EngineeringNorth China Electric Power UniversityBaoding071003China

Although solid-state lithium electrolytes have the potential to reduce the safety issues associated with organic liquid electrolytes,disadvantages such as low total conductivity,large interface impedance,and delamination of the interface due to cyclic stress still need to be *** solid-state lithium-ion conductor Li_(0.33)La_(0.56)TiO_(3)(LLTO) was prepared via a hydrothermal route by using CTAB as templates in this *** LLTO with micro-porous channels was obtained and the total conductivity is comparable to the non-porous *** LLTO pellets are infiltrated with the non-porous LLTO precursor solution,and the total conductivities of the infiltrated porous LLTO are all higher than those without *** infiltration,the porous LLTO calcined at 600℃ achieves the highest total conductivity,7.88×10^(-5) S/*** fracture toughness of the infiltrated LLTO is higher than that of the non-porous *** results demonstrate a new way to prepare solid-state lithium-ion conductors with high ionic conductivity and great tolerance to cyclic stress.

关键词： Perovskite Porous material Infiltration Ionic conductors Fracture toughness Rare earths

Experimental investigation on coal pore-fracture variation and fractal characteristics synergistically affected by solvents for improving clean gas extraction

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International Journal of Mining Science and Technology 2024年第3期34卷 413-425页

作者： Feilin Han Sheng Xue Chunshan Zheng Zhongwei Chen Guofu Li Bingyou Jiang key laboratory of Safe and Effective coal Mining of Ministry of Education Anhui University of Science and TechnologyHuainan 232001China School of Safety Science and Engineering Anhui University of Science and TechnologyHuainan 232001China School of Mechanical and Mining Engineering University of QueenslandQLD 4072Australia State key laboratory of coal and coalbed Methane Co-Mining Jincheng 048012China

Chemical solvents instead of pure water being as hydraulic fracturing fluid could effectively increase permeability and improve clean methane extraction ***,pore-fracture variation features of lean coal synergistically affected by solvents have not been fully *** testing,nuclear magnetic resonance analysis,liquid phase mass spectrometry was adopted to comprehensively analyze pore-fracture change characteristics of lean coal treated by combined solvent(NMP and CS_(2)).Meanwhile,quantitative characterization of above changing properties was conducted using geometric fractal *** model between permeability,fractal dimension and porosity were *** indicate that the end face fractures of coal are well developed after CS2and combined solvent treatments,of which,end face box-counting fractal dimensions range from 1.1227 to *** decreases in ultrasonic longitudinal wave velocity of coal affected by NMP,CS_(2)and combined solvent are 2.700%,20.521%,22.454%,*** treatments could lead to increasing amount of both mesopores and *** ratio of fractal dimension Dsis 0.259%–2.159%,while permeability increases ratio of NMR ranges from 0.1904 to ***,combined solvent could dissolve coal polar and non-polar small molecules and expand flow *** could provide reference for solvent selection and parameter optimization of permeability-enhancement technology.

关键词： Clean gas extraction Chemical solvent Experimental investigation Fractal characteristics Pore fracture