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Component fractionation of wood-tar by column chromatography with the packing material of silica gel

Chinese Science Bulletin 2011年第14期56卷 1434-1441页

作者： WANG Ze LIN WeiGang SONG WenLi DU Lin LI ZhengJie YAO JianZhong State Key Laboratory of Multi-Phase Complex System Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China

Bio-oil can be an important fuel resource for automobiles in the future,while its complex composition restricts the direct application of the bio-oil *** it is necessary to separate the complex mixture to relatively simplified fractions for goal directed specific treatments to reach the fuel quality for automobiles,and meanwhile different functional chemical materials and fine chemicals can be *** it is significant to investigate the bio-oil component separating *** the method of column chromatography by the packing material of silica gel with two series of eluants of cyclohexane-benzene-methanol and cyclohexane-dichloromethane-methanol were investigated for component fractionation of the raw wood tar (oil fraction of the liquid product by slow pyrolysis of wood).The analytical results show that the components in cyclohexane are rich in alkoxyl-monophenols;the components of alkyl-monophenols and five ring oxygen-containing compounds are abundant in benzene and in dichloromethane similarly;in the methanol fraction,the components are diverse and diphenols are relatively in higher content,comparatively small polar molecules and five ring oxygen-containing compounds are more abundant in the methanol fraction after being eluted by dichloromethane,and the content of 1-(4-hydroxy-3-methoxyphenyl)-2-propanone is higher after being eluted by benzene.

关键词：包装材料木焦油硅胶分馏成分柱层析含氧化合物二氯甲烷

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Analysis of cutting-edge techniques in the high voltage and high power adjustable speed drive systems

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Science China(Technological Sciences) 2009年第2期52卷 442-449页

作者： ZHAO ZhengMing BAI Hua YUAN LiQiang State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Electrical EngineeringTsinghua UniversityBeijing 100084China

The high voltage and high power adjustable speed drive (ASD) system is one of the most attractive fields in power electronics, and it is also a very crucial technique for energy saving and emission reduction. This paper discussed and analyzed the main cutting-edge knowledge and issues in the process of exploiting the high voltage and high power ASD system.

关键词： high voltage and high power inverter safe operation area pulse and pulse sequence

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Functionally graded composite ceramics: design, manufacturing, properties and applications

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Progress in Materials Science 2025年 154卷

作者： Zheng, Yingqi Sun, Jialin Li, Xiao Zhao, Jun Wang, Haibin Yun, Xialun Li, Zhuan Huang, Zhifu School of Mechanical Electrical & Information Engineering Shandong University Weihai264209 China Shenzhen Research Institute of Shandong University Shenzhen518057 China State Key Laboratory for Powder Metallurgy Central South University Changsha410083 China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou730000 China Weihai Weiying Tool Co. Ltd. Weihai264210 China Key Laboratory of High Efficiency and Clean Mechanical Manufacture of MOE School of Mechanical Engineering Shandong University Jinan250061 China College of Materials Science and Engineering Key Laboratory of Advanced Functional Materials Education Ministry of China Beijing University of Technology Beijing100124 China State Key Laboratory for Manufacturing System Engineering School of Mechanical Engineering Xi'an Jiaotong University Xi'an710049 China State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and Engineering Xi'an Jiaotong University Xi'an710049 China

Functionally graded ceramics (FGCs) are a class of advanced ceramic materials with spatially varying composition, phase or microstructure, designed to achieve continuous or discrete variations in material properties through advanced techniques. They have played a crucial role in replacing conventional ceramic materials in advanced applications as a function of its superior performance in balancing mutually exclusive properties (toughness and strength etc.). Herein, we apply towards comprehensively discuss the emerging advancements in FGCs, highlighting their design, manufacturing, properties and applications. Different design principles were discussed from structural design, stress design, composition design to computer-aided design. Furthermore, in-depth perspective analysis of advanced processing technologies was summarized including powder metallurgy, slip casting, and additive manufacturing. Additionally, the thermal and mechanical properties of FGCs were summarized, accompanied by the corresponding property enhancement mechanisms. Finally, the critical challenges and potential applications in further developing functionally graded ceramics were provided. This comprehensive overview of FGC would be referenceable and helpful to the researchers working in this area or new-come to this field, thereby identifying the research gaps for advancing the field. © 2025 Elsevier Ltd

关键词： Porcelain

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The simulation modeling and validation by wind tunnel experimentation for optical transmission effect of high speed turbulence flow

The simulation modeling and validation by wind tunnel experi...

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International Symposium on Photoelectronic Detection and Imaging 2009: Advances in Infrared Imaging and Applications

作者： Fei, Jindong Zhan, Liqin Chen, Cheng Gao, Yang Key Laboratory of System Simulation Beijing Simulation Center China Beijing Electronic System Engineering Institute China

ISBN: (纸本)9780819476647

The high speed turbulence flow is a medium provided with high speed variety and heterogeneous, it has characteristics of time correlation and space correlation. The detection performance of optical imaging detecting system on a flight viechle is influenced by the high speed turbulence flow, when the light wave of a target pass through it. The transmission theory of light wave passing through the turbulent flow field was presented in the paper, and the influence principle about it on the imaging detection system was also analyzed. The simulation result based on the theory also presented. Finally, a comparison the calculating result with the result by wind tunnel experimentation has been discussed. © 2009 SPIE.

关键词： Wind tunnels

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A coevolutionary framework of business-IT alignment via the lens of enterprise architecture

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Journal of systems engineering and Electronics 2020年第5期31卷 983-995页

作者： LIN Menglong YI Shuanghui ZHANG Mengmeng CHEN Tao CHEN Honghui ZHANG Xiaoxue Science and Technology on Information Systems Engineering Laboratory National University of Defense TechnologyChangsha 410072China National Key Laboratory for Complex System Simulation Academy of Military SciencesBeijing 100000China

Due to the turbulent external business environment, the complexity of internal relations of the organization and the emergence of subversive IT roles, the business-IT alignment(BITA)has become increasingly difficult. The unsuccessful realization of BITA will lead to the waste of organizational resources, the reduction of return on investment and eventually the loss of competitive advantage. In recent years, coevolution has received widespread attention due to its ability to describe the dynamic relationship between IT and business. Multiple principles such as quickening learning action loops and adopt suitable organizing principles for achieving business and IT coevolution(BITC) are obtained. However, the continuous BITC is still hard to be achieved because of the lack of complete BITC management. This paper focuses on the management process of the BITC and how to perform it gradually. A coevolution framework combines the enterprise architecture(EA) approach with the coevolution analysis is proposed, which contains the design of EA, the sensing and governance of the misalignment and the procedure of the EA misalignment *** steps for the governance and prevention of misalignment are discussed in particular. Through comparison with the principles,characteristics and methods of coevolution in the literature, the proposed framework is evaluated. The results show that the proposed framework is effective for BITC implementation.

关键词： business-IT alignment(BITA) coevolution misalignment governance misalignment prevention enterprise architecture

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Nonlinear impedance control with trajectory adaptation for collaborative robotic grinding

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Science China(Technological Sciences) 2023年第7期66卷 1928-1936页

作者： HAN FengTao TAM SikYuen CAO ZhiHong ZHAO XingWei TAO Bo DING Han State Key Laboratory of Intelligent Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China State Key Laboratory of Intelligent Manufacturing System Technology for Complex Products Beijing Institute of Electronic System EngineeringBeijing 100854China ROKAE(Beijing)Technology Co. Ltd.Beijing 100193China

Stiffness adjustment is an important feature of human arm *** adaptive variable impedance control can adapt to the robotic stiffness,but may result in a large *** this paper,nonlinear impedance control is proposed for collaborative robotic grinding,where nonlinear force feedback is designed to compensate for the nonlinear stiffness of the ***,the interaction system can be linearization to ensure the system ***,a target trajectory adaptation strategy is studied to ensure the force tracking ***,switching law between trajectory tracking and force tracking is proposed when the robot performs a complex grinding *** stability of the switch control as well as the trajectory adaptation law is *** are conducted in a robotic grinding test rig,where the robot is used to grind a turbine *** results show that the nonlinear impedance control can obtain stable grinding force,and have better grinding quality than the linear impedance control.

关键词： impedance control robotic grinding trajectory adaptation force tracking

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Optimization and Mechanical Accuracy Reliability of a New Type of Forging Manipulator

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Chinese Journal of Mechanical engineering 2015年第2期28卷 236-248页

作者： CHEN Kang MA Chunxiang ZHENG Maoqi GAO Feng State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong University Beijing Aerospace Systems Engineering Institute

Researches on forging manipulator have enormous influence on the development of the forging industry and national *** device and lifting mechanism are the core parts of forging manipulator,and have been studied for longer ***,the optimization and mechanical accuracy reliability of them are less *** on General Function（G_F）set and parallel mechanism theory,proper configuration of 10t forging manipulator is selected firstly.A new type of forging manipulator driven by cylinders is *** solved mechanical analysis of manipulator＇s core mechanisms,expressions of force of cylinders are carried *** order to achieve smaller force afforded by cylinders and better mechanical characteristics,some particular sizes of core mechanisms are optimized intuitively through the combined use of the genetic algorithms（GA）and GUI interface in *** with the original mechanisms,optimized clamp saves at least 8 percent efforts and optimized lifting mechanism 20 percent under maximum working ***,considering the existed manufacture error of components,mechanical accuracy reliability of optimized clamp,lifting mechanism and whole manipulator are demonstrated respectively based on fuzzy reliability *** results show that the accuracy reliability of optimized clamp is bigger than 0.991 and that of optimized lifting mechanism is *** the whole manipulator under maximum working condition,that value exceeds 0.986 4,which means that optimized manipulator has high motion accuracy and is reliable.A new intuitive method is created to optimize forging manipulator sizes efficiently and more practical theory is utilized to analyze mechanical accuracy reliability of forging manipulator precisely.

关键词： forging manipulator G_F set configuration optimization mechanical reliability

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Behavior-based cooperative control method for fixed-wing UAV swarm through a virtual tube considering safety constraints

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Chinese Journal of Aeronautics 2025年

作者： Siyi YUE Duo ZHENG Mingjun WEI Zhichen CHU Defu LIN School of Astronautics Engineering Beijing Institute of Technology Beijing 100081 China National Key Laboratory of Complex System Control and Intelligent Agent Cooperation Yungang Street Beijing 100074 China

Unmanned Aerial Vehicle (UAV) swarm collaboration enhances mission effectiveness. However, fixed-wing UAV swarm flights face collaborative safety control problems within a limited airspace in complex environments. Aimed at the cooperative control problem of fixed-wing UAV swarm flights under the airspace constraints of a virtual tube in a complex environment, this paper proposes a behavior-based distributed control method for fixed-wing UAV swarm considering flight safety constraints. Considering the fixed-wing UAV swarm flight problem in complex environment, a virtual tube model based on generator curve is established. The tube keeping, centerline tracking and flight safety behavioral control strategies of the UAV swarm are designed to ensure that the UAV swarm flies along the inside of the virtual tube safety and does not go beyond its boundary. On this basis, a maneuvering decision-making method based on behavioral fusion is proposed to ensure the safe flight of UAV swarm in the restricted airspace. This cooperative control method eliminates the need for respective pre-planned trajectories, reduces communication requirements, and achieves a high level of intelligence. simulation results show that the proposed behavior-based UAV swarm cooperative control method is able to make the fixed-wing UAV swarm, which is faster and unable to hover, fly along the virtual tube airspace under various virtual tube shapes and different swarm sizes, and the spacing between the UAVs is larger than the minimum safe distance during the flight.

关键词： Unmanned aerial vehicles (UAV) UAV swarm Distributed cooperative control Swarm flight safety Behavior-based method Virtual tube airspace

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Modeling the dynamic alignment of business and information systems via the lens of human-centered architecture evolution

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Journal of systems engineering and Electronics 2021年第4期32卷 881-888页

作者： ZHANG Mengmeng YI Shuanghui CHEN Honghui LUO Aimin LIU Junxian ZHANG Xiaoxue Science and Technology on Information Systems Engineering Laboratory National University of Defense TechnologyChangsha 410072China National Key Laboratory for Complex System Simulation Military Academy of SciencesBeijing 100080China

The complexity of business and information systems(IS)alignment is a growing concern for researchers and practitioners *** extant research on alignment architecture fails to consider the human viewpoint,which makes it difficult to embrace emergent *** paper contributes to the extant literature in the following ***,we combine an enterprise architecture(EA)framework with a human viewpoint to address alignment issues in the architecture design phase;second,we describe a dynamic alignment model by developing a humancentered meta-model that explains first-and second-order changes and their effects on alignment *** paper provides better support for the theoretical research and the practical application of dynamic alignment.

关键词： business and information systems(IS)alignment human viewpoint enterprise architecture(EA) meta-model dynamic alignment

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Curvature-property coupling governed heat transfer deterioration in supercritical helically coiled tubes: Mechanistic insights and mitigation strategies via structural parametrization

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International Journal of Thermal Sciences 2025年 215卷

作者： Chang, Fucheng Xin, Jiaxing Wu, Xiaoyi Li, Liwei Li, Huixiong Zhu, Yanlin National Key Lab of Aerospace Power System and Plasma Technology School of Mechanical Engineering Xi'an Jiaotong University Xi'an 710049 China China Special Equipment Testing and Research Institute Beijing 100029 China State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi'an Jiaotong University Xi'an 710049 China Shanghai Nuclear Engineering Research & Design Institute Co. Ltd Shanghai 200233 China

The unique thermo-hydrodynamic coupling phenomena in the helically coiled tube (HCT) handling supercritical fluids present both opportunities and challenges for next-generation compact heat exchangers. While the pronounced thermophysical property variations near pseudo-critical temperatures (T_pc) and curvature-induced secondary flows synergistically enhance heat transfer coefficient (HTC), their nonlinear coupling mechanisms may unexpectedly provoke severe heat transfer deterioration (HTD). Through systematic numerical investigations, this study reveals that circumferential wall temperature inhomogeneity (CWTI) exhibits an inverted N-shaped evolution, providing valuable insights for thermal homogenization design near T_pc. The secondary flow Reynolds number (Se), quantifying secondary flow intensity, shows a monotonic increase with decreasing coil diameter (D_c) or inner diameter (D_i), reaching saturation in high-enthalpy regions. Notably, CWTI demonstrates non-monotonic behavior, achieving minimum values near T_pc before manifesting distinct rebound characteristics near T_pc conditions. Parametric analysis establishes that: (1) Elevating heat flux (q) increases Se, reducing D_c boosts it by 50.3 %, and decreasing D_i raises it by 60.0 %. (2) HTD predominantly initiates at the outer wall under high-q conditions, with D_c reduction achieving HTD suppression and 26.9 % enhancement in the local HTC;(3) Reducing the D_i results in a reduction of maximum CWTI by 22.5 %–28.6 %, suggesting that structural parametrization effectively mitigates wall temperature non-uniformity, thus suppressing the HTD. While centered on supercritical water, the dimensionless scaling relationships demonstrate extendibility to other media, with the curvature-property coupling mechanism both elucidating fundamental interactions and guiding robust heat exchanger design. © 2025 Elsevier Masson SA

关键词： Heat transfer deterioration Helically coiled tube Structural parametrization Supercritical fluid Thermo-hydrodynamic coupling

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