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Experimental and numerical study of combustion characteristics of ammonia-hydrogen-air swirling flame with/without secondary air injection

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Chinese Journal of Aeronautics 2024年第4期37卷 243-255页

作者： Chunyu liu Chenhu GAO Yue HUANG Hua JIN Dan ZHAO Wenjiang xu Yancheng YOU school of Aerospace engineering Xiamen UniversityXiamen 361005China school of mechanical engineering Shanghai Jiao Tong UniversityShanghai 200240China Department of mechanical engineering University of CanterburyChristchurch 8041New Zealand

Ammonia (NH_(3.) is currently considered to be a potential carbon-free alternative fuel,and its large-scale use as such would certainly decrease greenhouse gas emissions and meet increasingly stringent emission *** the low flame propagation speed and high NO production of NH_(3. hinder its direct application as a renewable fuel,co-combustion of NH_(3.–H_(2)is an effective way to overcome these *** this study,the combustion characteristics of NH_(3.–H_(2)swirling flames under different equivalence ratios and H_2blending ratios conditions are both numerically and experimentally ***,the One-Dimensional (1D) laminar flame computation presents a comparison base and the Three-Dimensional (3.) numerical simulation yields detailed flame property ***,the high-speed camera takes instantaneous swirl flame images and the gas analyzer measures the NO emission at the exit plane of the flame *** and quantitative analysis is performed on the flame structure and NO emission for a series of NH_(3.–H_(2)swirl *** variation trends of the NO emission calculated using different techniques agree very *** quantitative results show that the NO emissions are much higher at lean equivalence ratios than those at rich equivalence ratios,and such difference is closely related to the combustion flame ***,it is shown that the utilization of secondary air injection can achieve a significant reduction in NO emissions at the exit of the combustion chamber at equivalence ratios less than or equal to 0.9.

关键词： Ammonia combustion Swirling flow NO emission characteristics Secondary combustion Chemical reaction mechanism

Development of multi-functional anchorage support dynamic-static coupling performance test system and its application

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International Journal of Mining science and Technology 2024年第3期34卷 339-349页

作者： Qi Wang Shuo xu Bei Jiang Chong Zhang Zhe Sun Jingxuan liu Cailin Jiao State Key Laboratory for Tunnel engineering China University of Mining&Technology-BeijingBeijing 100083China Research Center of Geotechnical and Structural engineering Shandong UniversityJinan 250061China

In underground engineering with complex conditions,the bolt(cable)anchorage support system is in an environment where static and dynamic stresses coexist,under the action of geological conditions such as high stresses and strong disturbances and construction conditions such as the application of high *** is essential to study the support components performance under dynamic-static coupling *** on this,a multi-functional anchorage support dynamic-static coupling performance test system(MAC system)is developed,which can achieve 7 types of testing functions,including single component performance,anchored net performance,anchored rock performance and so *** bolt and cable mechanical tests are conducted by MAC system under different prestress *** results showed that compared to the non-prestress condition,the impact resistance performance of prestressed bolts(cables)is significantly *** the prestress range of 50–160 k N,the maximum reduction rate of impact energy resisted by different types of bolts is 53.9%–61.5%compared to non-prestress *** the prestress range of 150–3.0 k N,the impact energy resisted by high-strength cable is reduced by76.8%–84.6%compared to non-prestress *** MAC system achieves dynamic-static coupling performance test,which provide an effective means for the design of anchorage support system.

关键词： Anchorage support system Development of test system Dynamic-static coupling test Combined stress

Rapid health estimation of in-service battery packs based on limited labels and domain adaptation

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Journal of Energy Chemistry 2024年第2期89卷 345-354,I0009页

作者： Zhongwei Deng Le xu Hongao liu Xiaosong Hu Bing Wang Jingjing Zhou school of mechanical and Electrical engineering University of Electronic Science and Technology of ChinaChengdu 611731SichuanChina school of Sustainability Stanford UniversityStanfordCA 94305USA College of mechanical and Vehicle engineering Chongqing UniversityChongqing 400044China china Automotive engineering Research Institute Co.Ltd. Chongqing 401122China

For large-scale in-service electric vehicles(EVs)that undergo potential maintenance,second-hand transactions,and retirement,it is crucial to rapidly evaluate the health status of their battery ***,existing methods often rely on lengthy battery charging/discharging data or extensive training samples,which hinders their implementation in practical *** address this issue,a rapid health estimation method based on short-time charging data and limited labels for in-service battery packs is proposed in this ***,a digital twin of battery pack is established to emulate its dynamic behavior across various aging levels and inconsistency ***,increment capacity sequences(△Q)within a short voltage span are extracted from charging process to indicate battery ***,data-driven models based on deep convolutional neural network(DCNN)are constructed to estimate battery state of health(SOH),where the synthetic data is employed to pre-train the models,and transfer learning strategies by using fine-tuning and domain adaptation are utilized to enhance the model ***,field data of 10 EVs exhibiting different SOHs are used to verify the proposed *** using the△Q with 100 m V voltage change,the SOH of battery packs can be accurately estimated with an error around 3.2%.

关键词： Lithium-ion battery Electric vehicles Health estimation Feature extraction Convolutional neural network Domain adapatation

A creep model for ultra-deep salt rock considering thermal-mechanical damage under triaxial stress conditions

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Journal of Rock Mechanics and Geotechnical engineering 2024年第2期16卷 588-596页

作者： Chao Liang Jianfeng liu Jianxiong Yang Huining xu Zhaowei Chen Lina Ran College of Water Resource and Hydropower Sichuan UniversityChengdu610065China CNPC Key Laboratory of Oil and Gas Underground Storage engineering Langfang065007China CNPC engineering Technology R&D Company Limited Beijing102206China

To investigate the specific creep behavior of ultra-deep buried salt during oil and gas exploitation,a set of triaxial creep experiments was conducted at elevated temperatures with constant axial pressure and unloading confining pressure *** results show that the salt sample deforms more significantly with the increase of applied temperature and deviatoric *** accelerated creep phase is not occurring until the applied temperature reaches 13.℃,and higher temperature is beneficial to the occurrence of accelerated *** describe the specific creep behavior,a novel three-dimensional(3.)creep constitutive model is developed that incorporates the thermal and mechanical variables into mechanical ***,the standard particle swarm optimization(SPSO)method is adopted to fit the experimental data,and the sensibility of key model parameters is analyzed to further illustrate the model *** a result,the model can accurately predict the creep behavior of salt under the coupled thermo-mechanical effect in deep-buried *** on the research results,the creep mechanical behavior of wellbore shrinkage is predicted in deep drilling projects crossing salt layer,which has practical implications for deep rock mechanics problems.

关键词： Creep experiments Creep model Thermal and mechanical damage Fractional derivative

Effects of Er on the microstructure and properties of AZ3. magnesium alloy prepared via the EMS process

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Rare Metals 2010年第4期29卷 339-345页

作者： MA Yutao,ZHANG Xingguo,liu Hongbin,and MENG Linggang school of Materials science and {3.,Dalian university of Technology,Dalian 116023.china school of Materials science and engineering Dalian University of Technology Dalian China

The effects of small amounts of the rare-earth element erbium on the microstructure and the mechanical properties of AZ3. magnesium alloy via the electromagnetic stirring （EMS） process have been studied. It has been shown that AZ3.-Er alloys are mainly composed of α-Mg solid solution and β-Mg17TA112 phases. When the Er content reaches 0.12 wt.%, the characteristic peaks of A12Er can be observed. The micro- structure is obviously refined and the tensile strength of the AZ3.-based alloy at ambient temperature is significantly improved by contents of 0.03.wt.% Er, especially the elongation （8= 19%）. More addition of Er obviously decreases the tensile strength and elongation of the AZ3.-based alloy because of the grain coarsening and the reduction of β-Mg17A112 phases.

关键词： AZ3. magnesium alloy microstructure mechanical properties erbium

NEW DEVELOPMENT IN DOUBLE GLOW SURFACE ALLOYING TECHNOLOGY

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Chinese Journal of mechanical engineering 2002年第2期15卷 186-188页

作者： xu Zhong liu Xiaoping Li Zhonghou Research Institute of Surface engineering, Taiyuan {3. of Technology, Taiyuan 03.024, chinaXie Xishan Zhang xu {3. of science and Technology beijing *** Research Institute of Surface engineering Taiyuan University of Technology Taiyuan 030024 China

Several kinds of special alloys are produced on the surfaces of iron andsteels by using double glow surface alloying technology. Surface Ni-Cr-Mo-Nb alloy, surfaceprecipitation hardening high speed steel and surface p... 详细信息

关键词： Precipitation hardening Alloying Hardness Corrosion resistance

Comparison study of trapped water in human erythrocytes by EPC and DSC method and its application

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science china(Technological sciences) 2004年第3期47卷 343-351页

作者： ZHAO Gang1, HE Liqun1, GUO Xiaojie2, liu Zhong3. LUO Dawei1,3.& GAO Dayong1,3.1. Cryobiomedical engineering Research Institute, Department of Thermal science and Energy engineering, university of science and Technology of china, Hefei 23.027, china 2. Red Cross Blood Center of Hefei, Hefei 23.022, china 3. Department of mechanical engineering, university of Kentucky, Lexington, KY 40506-0108, USA Univ Sci & Technol china Cryobiomed Engn Res Inst Dept Thermal Sci & Energy Engn Hefei 230027 Peoples R China Red Cross Blood Ctr Hefei Hefei 230022 Peoples R China Univ Kentucky Dept Mech Engn Lexington KY 40506 USA

The novel differential scanning calorimetry method for determining trapped water volume of human red blood cell during freezing process has been reexamined. Results show that the final erythrocyte volume is 53. of its isotonic volume after freezing to -40℃. An electronic particle counter (MultisizerTM III, Beckman Coulter Inc., USA) was used to measure cell volume changes in response to hypertonic solution. Using this approach, when extracellular solution was 3.86 mOsm, the equilibrium cell volume was found to be 57% of its isotonic value. Both results indicate that 3.%—40% of intracellular water is trapped and cannot respond to osmotic difference between intra- and extracellular solution. These findings are consistent with the published data: at least 20%—3.% of the isotonic cell water volume is retained within RBCs during freezing. Some applications of the values of trapped water are addressed.

关键词： differential scanning calorimeter/DSC, electronic particle counter/EPC, cell volumetric change, red blood cell/RBC/erythrocyte

STUDY ON SINGULAR CONFIGURATIONS AND COMPUTER SIMULATION OF 6R ROBOT

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Chinese Journal of mechanical engineering 2004年第2期17卷 177-180页

作者： Zhang Kai Hu Dejin liu Chengliang school of mechanical {3.,Shanghai Jiaotong university,Shanghai 20003., china school of mechanical engineering Shanghai Jiaotong University 上海 200030

When robot is at singular configuration, the limited hand velocity wouldrequire some joints with infeasible speeds so as to lead unsafely of the system. A method of solvingthe approximate velocity of joint near singular configuration point by adding damped vector isproposed and a modified algorithm is provided. With the analysis of J^(-1) the singularconfigurations of 6R robot are divided into structure boundary singularity , boundary singularity ,inner singularity and wrist singularity. The conditions of singularities of the robot have beenascertained. The computer simulations of the singularities of the robot are developed, which havemany advantages over previous description methods of the singular configurations of robot. With thehelp of boundary singularity analysis, a application in welding trajectory planning checking of therobot has been carried out and the simulation result proved visualized and useful.

关键词： Robot Singular configuration Computer simulation

Spatial light modulation for femtosecond laser manufacturing:Current developments and challenges

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science china(Technological sciences) 2024年第1期67卷 60-72页

作者： ZANG xue liu ZiTing xu YiShi WANG Yi WANG Qing LI ZhenZe WANG Lei State Key Laboratory of Integrated Optoelectronics College of Electronic Science and EngineeringJilin UniversityChangchun 130012China State Key Laboratory of Precision Measurement and Instruments Department of Precision InstrumentTsinghua UniversityBeijing 100084China

Since the invention of lasers,spatial-light-modulated laser processing has become a powerful tool for various *** enables multidimensional and dynamic modulation of the laser beam,which significantly improves the processing efficiency,accuracy,and flexibility,and presents wider prospects over traditional mechanical technologies for machining three-dimensional,hard,brittle,or transparent *** this review,we introduce:(1)The role of spatial light modulation technology in the development of femtosecond laser manufacturing;(2)the structured light generated by spatial light modulation and its generation methods;and(3.representative applications of spatial-light-modulated femtosecond laser manufacturing,including aberration correction,parallel processing,focal field engineering,and polarization ***,we summarize the present challenges in the field and possible future research.

关键词： femtosecond laser manufacturing spatial light modulation structured light aberration correction parallel processing focal field engineering polarization control