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Lighting up nonbenzenoid acepleiadylene with ultra-narrowband emission through aromaticity modulation

Science China Chemistry 2023年第12期66卷 3506-3510页

作者： Pengcai Liu Xiao-Yu Tang cheng-zhuo du Rui Xue Xing-Yu Chen Jiawen Cao Xiao-Ye Wang State Key Laboratory of Elemento-Organic Chemistry Frontiers Science Center for New Organic MatterCollege of ChemistryNankai UniversityTianjin 300071China

Nonbenzenoid polycyclic arenes have attracted great attention because of their unique topological structures and appealing properties;however,they are generally considered as poor luminescent materials due to the ring puckering behavior of the ***(APD),a nonbenzenoid isomer of pyrene,has been demonstrated as an excellent building block for optoelectronic applications,but its poor photoluminescence quantum yield(PLQY)has hampered its application in luminescent *** that the ring puckering character can be suppressed by increasing the rigidity of the nonhexagon rings,herein,we propose a novel strategy for enhancing the aromaticity of the nonhexagons to improve the PLQYs of APD ***-withdrawing cyano groups are introduced on the five-membered ring of APD to enhance the chargeseparated character and thus the aromaticity of the nonhexagons,endowing the cyano-substituted APDs(CNAPD and 2CNAPD)with better ***,the cyano substitution successfully suppresses the nonradiative energy dissipation caused by the ring puckering,improving the PLQY from 2.4%for APD to 14%for CNAPD,and to 63%for *** addition,the enhanced rigidity also suppresses the vibration sideband of the photoluminescence spectra,leading to an ultra-narrowband emission from 2CNAPD with a full-width at half-maximum(FWHM)of 13 nm(47 me V),which is a new record in organic *** results demonstrate that APD derivatives have great potential in highly efficient luminescent materials with high color purity via the aromaticity regulation strategy,which provides a novel concept for designing nonbenzenoid luminescent materials.

关键词： nonbenzenoid arenes luminescence narrowband emission acepleiadylene

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Non-synchronous vibration of rotor blade in a six-stage transonic compressor

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Chinese Journal of Aeronautics 2024年第8期37卷 36-48页

作者： Ronghui cheng zhuo WANG Huawei YU Lin du Yi ZHANG Xiaofeng SUN Aeroengine Research Institute Beihang UniversityBeijing 102206China School of Energy and Power Engineering Beihang UniversityBeijing 102206China

This paper presents an experimental study on the Non-Synchronous Vibration(NSV)in a six-stage transonic *** first part of the paper describes the NSV phenomenon of Rotor 1,which occurs when both Stator 1(S1)and Stator 2(S2)or S1 only are *** measurements and analysis are carried out for the former case through the unsteady wall pressure and the Blade Strain(BS).The spinning mode theory used in the rotor/stator interaction noise is employed to explain the relation between the circumferential wave number of the aerodynamic disturbance and the Nodal Diameter(ND)of the blade *** variations of the vibration amplitudes of different blades and the Inter-Blade Phase Angles(IBPAs)at different moments suggest that the evolution of NSV is a highly nonuniform phenomenon along the circumferential *** addition,the difference between the wall-pressure spectra generated by the NSV and the classic flutter has been *** the second part,the variations of aerodynamic loading due to the adjustment of the staggers of the Inlet Guide Vane(IGV),S1 and S2 have been *** is found that closing S1 only can result in a great fluctuation to the performance of the front stages,which might be detrimental to the flow organization and increase the risk of *** contrast,the effect of closing S2 only on the performance of the first two stages appears to be slighter relatively.

关键词： Transonic compressor Non-synchronous vibration Modal analysis Aerodynamic loading Nodal diameter

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Development of X-FEM methodology and study on mixed-mode crack propagation

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Acta Mechanica Sinica 2011年第3期27卷 406-415页

作者： zhuo Zhuang Bin-Bin cheng School of Aerospace Tsinghua University 100084 Beijing China

The extended finite element method（X-FEM） is a novel numerical methodology with a great potential for using in multi-scale computation and multi-phase coupling problems. The algorithm is discussed and a program is developed based on X-FEM for simulating mixed-mode crack propagation. The maximum circumferential stress criterion and interaction integral are deduced. Some numerical results are compared with the experimental data to prove the capability and efficiency of the algorithm and the program. Numerical analyses of sub-interfacial crack growth in bi-materials give a clear description of the effiect on fracture made by interface and loading condition.

关键词： X-FEM - Mixed-mode fracture . Bi-material Sub-interfacial crack

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Numerical Research on the Influence of Deborah Number on Flow and Heat Transfer of Maxwell Fluid in a Tube with Laminar Pulsating Flow

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Journal of Thermal Science 2020年第4期29卷 972-981页

作者： WANG Zhipeng cheng Shuhao zhuo Yuqun Key Laboratory for Thermal Science and Power Engineering of the Ministry of Education Department of Energy and Power EngineeringTsinghua UniversityBeijing 100084China Beijing Engineering Research Center for Ecological Restoration and Carbon Fixation of Saline–alkaline and Desert Land Tsinghua UniversityBeijing 100084China China Institute of Atomic Energy Beijing 102413China

The flow and heat transfer characteristics of Maxwell fluid in a pipe under pulsating pressure gradient were studied. The governing equations were made dimensionless. The Rubin boundary condition was adopted. The flow field was solved theoretically and the temperature field was obtained using finite volume method. A general model suitable for various fluctuating characteristics and physical parameters was established. The Deborah number(De) was used to characterize the fluidity of the fluid. The influence of De on flow and temperature fields was evaluated. The Nusselt number and start-up process of Maxwell fluid were studied. Results showed that the influence of De on flow field was greater than that on temperature field. The effect of De on Nusselt number was irregular and related to the oscillation parameters. The over-shooting amplitude and oscillation time of axis center velocity in start-up flow grow larger with De.

关键词： Maxwell fluid pulsating flow Hagen-Poiseuille law Deborah number start-up flow

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Programming Shape-Morphing Behavior of Zwitterionic Polymer/Liquid Crystal Composite with Humidity-responsive Self-healing Performance

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Chinese Journal of Polymer Science 2023年第2期41卷 212-221页

作者： Shao-Jun Chen Hui-Feng cheng Bin du Jiao-Shi Liu Wen-Bo Shen Hai-Tao zhuo Shenzhen Key Laboratory of Polymer Science and Technology Guangdong Research Center for Interfacial Engineering of Functional MaterialsCollege of Materials Science and EngineeringShenzhen UniversityShenzhen518060China Shenzhen Key Laboratory of Functional Polymer College of Chemistry and Environmental EngineeringShenzhen UniversityShenzhen518060China

In this study,a zwitterionic polymer/liquid crystals composite film with programming shape-morphing behavior and humidityresponsive self-healing performance was prepared by blending a zwitterionic polymer and liquid crystalline azobenzene compound in solution,followed by film-forming in a mold without tedious or multistep synthetic *** as-obtained zwitterionic polymer/liquid crystal composite film exhibited programming shape-morphing behavior under different *** this process,the temporary shape of the composite film was memorized after the removal of the *** characteristics would fit the requirements of intelligence and energy-saving for stimuliresponsive shape-changing ***,the composite film showed humidity-responsive self-healing performances under wet conditions at room *** summary,the simple design and preparation route of the zwitterionic polymer/liquid crystal composite film with programming shape-morphing behavior and mild condition-responsive self-healing performance look promising for the fabrication and practical application of novel photo-driven devices and soft robotics.

关键词： Zwitterionic polymer Polymer/liquid crystals composite Programming shape-morphing behavior Humidity-responsive self-healing performance Stimuli-responsive shape-changing

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A novel enriched CB shell element method for simulating arbitrary crack growth in pipes

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Science China(Physics,Mechanics & Astronomy) 2011年第8期54卷 1520-1531页

作者： ZHUANG zhuo cheng BinBin School of Aerospace Tsinghua University Beijing 100084 China

In this work, a novel numerical method is developed for simulating arbitrary crack growth in pipes with the idea of enriched shape functions which can represent the discontinuity independent of the mesh. The concept of the enriched shape functions is introduced into the continuum-based (CB) shell element. due to the advantage of CB shell element, the shell thickness varia- tion and surface connection can be concerned during the deformation. The stress intensity factors of the crack in the CB shell element are calculated by using the 'equivalent domain integral' method for 3D arbitrary non-planar crack. The maximum en- ergy release rate is used as a propagation criterion. This method is proved able to capture arbitrary crack growth path in pipes which is independent of the element mesh. Numerical examples of different fracture patterns in pipes are presented here.

关键词： CB shell element enriched shape functions extended finite element 3D arbitrary crack propagation energy release rate

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Supervised Machine Learning Topological States of One-Dimensional Non-Hermitian Systems

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Chinese Physics Letters 2021年第7期38卷 6-10页

作者： zhuo cheng Zhenhua Yu Guangdong Provincial Key Laboratory of Quantum Metrology and Sensing School of Physics and AstronomySun Yat-Sen UniversityZhuhai 519082China State Key Laboratory of Optoelectronic Meterials and Technologies Sun Yat-Sen UniversityGuangzhou 510275China

We apply supervised machine learning to study the topological states of one-dimensional non-Hermitian *** Hermitian systems,the winding number of such non-Hermitian systems can take half *** focus on a non-Hermitian model,an extension of the Su-Schrieffer-Heeger *** non-Hermitian model maintains the chiral *** find that trained neuron networks can reproduce the topological phase diagram of our model with high *** successful reproduction goes beyond the parameter space used in the training *** analyzing the intermediate output of the networks,we attribute the success of the networks to their mastery of computation of the winding *** work may motivate further investigation on the machine learning of non-Hermitian systems.

关键词： process topological integers

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autoC: an efficient translator for model checking deterministic scheduler based OSEK/VDX applications

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Science China(Information Sciences) 2018年第5期61卷 141-155页

作者： Haitao ZHANG zhuo cheng Guoqiang LI Shaoying LIU School of Information Science and Engineering Lanzhou University School of Information Science Japan Advanced Institute of Science and Technology School of Software Shanghai Jiao Tong University Faculty of Computer and Information Sciences Hosei University

The OSEK/VDX automotive OS standard has been widely adopted by many automobile manufacturers, such as BMW and TOYOTA, as the basis for designing and implementing a vehicle-mounted OS. With the increasing functionalities in vehicles, more and more multi-task applications are developed based on the OSEK/VDX OS. Currently, ensuring the reliability of the developed applications is becoming a challenge for developers. As to ensure the reliability of OSEK/VDX applications, model checking as a potential solution has attracted great attention in the automotive industry. However, existing model checkers are often unable to verify a large-scale OSEK/VDX application that consists of many tasks, since the corresponding application model too complex. To make existing model checkers more scalable in verifying large-scale OSEK/VDX applications, we describe a software tool named auto C to tackle this problem by automatically translating a multi-task OSEK/VDX application into an equivalent sequential model. We conducted a series of experiments to evaluate the efficiency of auto C. The experimental results show that auto C is not only capable of efficiently sequentializing OSEK/VDX applications, but also of improving the scalability and efficiency of existing model checkers in verifying large-scale OSEK/VDX applications.

关键词： OSEK/VDX application deterministic scheduler software formal method model checking sequentialization

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Enhanced catalytic performance for direct synthesis of dimethyl ether from syngas over a La_2O_3 modified Cu-ZrO_2/γ-Al_2O_3 hybrid catalyst

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Journal of Natural Gas Chemistry 2012年第3期21卷 360-365页

作者： zhuo Li Jianqing Li cheng Yang Jinhu Wu Key Laboratory of Biofuels Qingdao Institute of Bioenergy and Bioprocess Technology Chinese Academy of Sciences Qingdao 266101 Shandong China Graduate School of Chinese Academy of Sciences Beijing 100039 China

A series of hybrid catalysts were made by physically mixing Cu-ZrO2 and γ-A12O3, for former it was modified with different loadings of La2O3 prepared by co-precipitation method. The catalysts were characterized by BET, XRD, N2O-adsorption, EXAFS, H2-TPR, NH3-TPD techniques and evaluated in the synthesis of dimethyl ether from syngas. The results show that La2O3 promoted catalysts displayed a significantly better catalytic performance compared with Cu-ZrO2#y-A12O3 catalyst in CO conversion and DME selectivity, and the optimum catalytic activity was obtained when the content of La2O3 was 12 wt%. The characterizations reveal that high copper dispersion, facile reducibility of copper particles and appropriate amount of acidic sites are responsible for the superior catalytic performance.

关键词： dimethyl ether syngas hybrid catalyst Cu-ZrO2 La2O3

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Formation of face-centered cubic titanium in laser surface re-melted commercially pure titanium plate

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Journal of Materials Science & Technology 2018年第5期34卷 767-773页

作者： zhuo Li Xu cheng Jia Li Huaming Wang national engineering laboratory of additive manufacturing for large metallic components school of materials science and engineeringbeihang university Beijing 100191 China

Micron-scale face-centered cubic titanium phase（named as δ phase） were noticed in the re-melted zone of laser surface re-melted commercially pure titanium *** morphology,sub-structure,orientation and distribution of δ phase were investigated by scanning electron microscopy,electron back-scattered diffraction and transmission electron *** kind formation processes of δ phase were put forward based on the *** first one is α＇→δ transformation which takes place in single α＇grains and leads to the orientation relationship {001}δ//{0001}α＇〈 110 〉 δ//〈 112^-0 〉α＇.The second one is β→α＇＋ δ transformation which takes place at α＇/α＇interfaces and leads to the orientation relationship{001}δ//{11^-0}β〈110〉 δ//〈111〉β.The third one is another kind of β→α＇＋ δ transformation that takes place at α＇/α＇interfaces and leads to the orientation relationship{11^-1}δ//{11^-0}β〈 110 〉 δ//〈 111 〈 β.It is believed that the transformations of δ phase are stress assistant ones and in the present investigation,the phase transformation stress of β→α＇transformation acts as the assistant driving force for the formation of δ phase.

关键词： Pure titanium Laser surface re-melt Martensitic phase transformation Face centered cubic Electron back-scattered diffraction

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