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Scheduling Storage Process of Shuttle-Based Storage and Retrieval Systems Based on Reinforcement Learning

Complex System Modeling and Simulation 2021年第2期1卷 131-144页

作者： Lei Luo ning zhao Gabriel Lodewijks School of Mechanical Engineering University of Science and Technology BeijingBeijing 100083China School of Aviation University of New South WalesSydney 2052Australia.

The Shuttle-Based Storage and Retrieval System(SBS/RS)has been widely studied because it is currently the most efficient automated warehousing *** of the related existing studies are focused on the prediction and improvement of the efficiency of such a system at the design ***,the control of existing SBS/RSs has been rarely *** existing SBS/RSs,some empirical rules,such as storing loads column by column,are used to control or schedule the storage *** question is whether or not the control of the storage process in an existing system can be improved further by using a different *** storage process is controlled to minimize the makespan of storing a series of loads into *** storage rules are easy to control,but they do not reach the minimum *** this study,the performance of a control system that uses reinforcement learning to schedule the storage process of an SBS/RS with fixed configurations is ***,a reinforcement learning algorithm called the actor-critic algorithm is *** algorithm is made up of two neural networks and is effective in making decisions and updating *** can also reduce the makespan relative to the existing empirical rules used to improve system *** results show that in an SBS/RS comprising six columns and six tiers and featuring a storage capacity of 72 loads,the actor-critic algorithm can reduce the makespan by 6.67%relative to the column-by-column storage *** proposed algorithm also reduces the makespan by more than 30%when the number of loads being stored is in the range of 7–45,which is equal to 9.7%–62.5%of the systems’storage capacity.

关键词： Shuttle-Based Storage and Retrieval System(SBS/RS) reinforcement learning scheduling

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A novel Ti-5.55Al-6.70Zr-1.50V-0.70Mo-3.41Nb-0.21Si alloy designed using cluster-plus-glue-atom model for laser additive manufacturing

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China Foundry 2023年第5期20卷 414-422页

作者： Tian-yu Liu Yan-chun Lou Shuang Zhang Zhi-hao Zhu Jun zhao Shi-bing Liu Kun Shi ning zhao National Key Laboratory of Advanced Casting Technologies Shenyang Research Institute of Foundry Co.Ltd.CAMShenyang 110022China School of Materials Science and Engineering Beihang UniversityBeijing 100191China School of Materials Science and Engineering Dalian Jiaotong UniversityDalian 116028LiaoningChina School of Materials Science and Engineering Dalian University of TechnologyDalian 116024LiaoningChina

A novel Ti-5.55Al-6.70Zr-1.50V-0.70Mo-3.41Nb-0.21Si alloy was designed using the cluster formula approach(cluster-plus-glue-atom model)and prepared by laser melting deposition(LMD).Its composition formula 12[Al-Ti_(12)](AlTi_(2))+5[Al_(0.8)Si_(0.2)-Ti_(12)Zr_(2)](V_(0.8)Mo_(0.2)Nb_(1)Ti)features an enhancedβ-Ti via co-alloying of Zr,V,Mo,Nb and *** experimental results show that the cluster formula ofαandβphases in the novel alloy are respectivelyα-[Al-Ti_(11.5)Zr_(0.5)](Al_(1)Ti_(2))andβ-[Al_(0.8)Si_(0.2)-Ti_(13.2)Zr_(0.8)](V_(1)Mo_(0.4)Nb_(1.6)),both containing Zr *** fitted composition via the α andβphase cluster formulas has little difference with the actual alloy composition,suggesting that the validity of cluster-plus-glue-atom model in the alloy composition *** hot isostatic pressing(HIP),both the Ti-6Al-4V and the novel alloy by LMD are characterized by prior-βcolumnar grains,while the typicaltexture *** with Ti-6Al-4V,Ti-5.55Al-6.70Zr-1.50V-0.70Mo-3.41Nb-0.21Si alloy exhibits a combination of higher strength(1,056 MPa)and higher ductility(14%)at room temperature and higher strength(580 MPa)at 550℃ after HIP,and can potentially serves as LMD materials.

关键词： additive manufacturing laser melting deposition novel titanium alloy composition design cluster-plus-glue-atom model

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The modification of titanium in mesoporous silica for Co-based Fischer–Tropsch catalysts

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Frontiers of Chemical Science and Engineering 2022年第8期16卷 1224-1236页

作者： Xin Li Meng Su Yao Chen Mehar UNisa ning zhao Xiangning Jiang Zhenhua Li Key Lab for Green Chemical Technology of Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Collaborative Innovation Center of Chemical Science and Engineering(Tianjin) Tianjin UniversityTianjin 300072China Research Institute of Petroleum Processing SINOPECBeijing 100083China

Ordered SBA-15 mesoporous silica with incorporated titanium was successfully synthesized via a onepot hydrothermal crystallization *** characterization including powder X-ray diffraction,Brunauer–Emmett–Teller,transmission electron microscope,temperatureprogrammed reduction,temperature-programmed desorption,Fourier transform infrared and ultraviolet-visible-near infrared spectrometer was performed to explore the physical and chemical structures of both the supports and the *** results showed that titanium was successfully incorporated into the mesoporous silica framework with a limited amount of titanium(Si/Ti>20),and the mesoporous structure was ***,the increased titanium content inevitably resulted in the formation of anatase TiO2 particles on the support *** increased incorporated titanium strengthened the interactions between cobalt species and supports,which was favorable for the cobalt species dispersion,despite the limited cobalt oxide *** enhanced metalsupport interactions were beneficial for the CO/H2 ratio at the active cobalt sites,which facilitated the formation of more C5+*** study provides a promising method for support modification with incorporatedheteroatoms for the rational development of Fischer–Tropsch catalysts.

关键词： Fischer–Tropsch synthesis titanium incorporation mesoporous silica metal-support interactions C5+selectivity

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Process design and economic optimization for the indirect synthesis of dimethyl carbonate from urea and methanol

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Chinese Journal of Chemical Engineering 2019年第8期27卷 1879-1887页

作者： Feng Wang Yanfeng Pu Jinhai Yang Taiying Wang Languang Chen ning zhao Fukui Xiao State Key Laboratory of Coal Conversion Institute of Coal Chemistry Chinese Academy of Sciences

Much attention has been paid for the synthesis of dimethyl carbonate(DMC) by urea indirect alcoholysis method, which had not been actually industrialized by now. The rigorous full process model was then necessary to optimize the process with heat integration. In this paper, a full process was designed and optimized for the DMC synthesis by urea indirect alcoholysis method based on Aspen Plus *** technological analysis was developed to find how the process was influenced by the three main recycled materials of methanol, 1,2-propylene glycol(PG) and mixture of DMC–methanol. Simultaneously,the thermal optimization was taken into account for energy saving and the optimized process was proposed with heat integration. Moreover, the economic evaluation was implemented for the optimized process with total annualized cost(TAC) and cost of product(COP) according to the plant investment and operations. It was found that the 11.6% decrease in TAC was obtained for the optimized process compared to the original designed process. The COP analysis showed that the process was economically efficient for the production of DMC from urea and methanol.

关键词： Dimethyl carbonate Process simulation Transesterification Urea

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A Robust Immersed Boundary-Lattice Boltzmann Method for Simulation of Fluid-Structure Interaction Problems

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Communications in Computational Physics 2016年第6期20卷 156-178页

作者： Jie Wu Jing Wu Jiapu Zhan ning zhao Tongguang Wang Department of Aerodynamics Nanjing University of Aeronautics and AstronauticsYudao Street 29Nanjing 210016JiangsuChina

A robust immersed boundary-lattice Boltzmann method(IB-LBM)is proposed to simulate fluid-structure interaction(FSI)problems in this *** with the conventional IB-LBM,the current method employs the fractional step technique to solve the lattice Boltzmann equation(LBE)with a forcing ***,the non-physical oscillation of body force calculation,which is frequently encountered in the traditional IB-LBM,is suppressed *** is of importance for the simulation of FSI *** the meanwhile,the no-slip boundary condition is strictly satisfied by using the velocity correction ***,based on the relationship between the velocity correction and forcing term,the boundary force can be calculated accurately and easily.A few test cases are first performed to validate the current ***,a series of FSI problems,including the vortex-induced vibration of a circular cylinder,an elastic filament flapping in the wake of a fixed cylinder and sedimentation of particles,are *** on the good agreement between the current results and those in the literature,it is demonstrated that the proposed IB-LBMhas the capability to handle various FSI problems effectively.

关键词： Immersed boundary-lattice Boltzmann method fractional step suppression of force non-physical oscillation fluid-structure interaction

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The Deep Geophysical Structure of the Middle Section of the Longmen Mountains Tectonic Belt and its Relation to the Wenchuan Earthquake

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Acta Geologica Sinica(English Edition) 2014年第2期88卷 483-497页

作者： YU Nian WANG Xuben HU Xiangyun CAI Xuelin KAN Aike zhao ning Institute of Geophysics and Geomatics China University of Geosciences Institute of Geophysics Chengdu University of Technology China railway Eryuan Engineering Group Co.Ltd State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation College of Information EngineeringChengdu University of Technology

Investigation of the deep geophysical structure of the Longmen Mountains tectonic belt and its relation to the Wenchuan Earthquake is important for the study of *** using magnetotelluric sounding profiles of the Luqu-Zhongjiang and Anxian-Suining; seismic sounding profiles of the Sichuan Maowen-Chongqing Gongtan,the Qinghai Huashi Gorge-Sichuan Jianyang,and the Batang-Zizhong; and magnetogravimetric data of the Longmen Mountains region,the deep geophysical structure of the Songpan-Ganzi block,the western Sichuan foreland basin,and the Longmen Mountains tectonic belt and their relation was *** eastward extrusion of the Qinghai-Tibet Plateau thrusts the Songpan-Ganzi block upon the Yangtze block,which obstructs the eastward movement of the Qinghai-Tibet *** Maoxian-Wenchuan,Beichuan-Yingxiu,and Anxian-Guanxian faults of the Longmen Mountains fault belt dip to northwest with different dip angles and gradually converge in the deeper *** structure suggests that an intracrustal low-velocity,low-resistivity,and high-conductivity layer is common between the middle and upper crust west of the Longmen Mountains tectonic belt but not in the upper Yangtze *** Sichuan Basin has a thick low-resistance sedimentary layer on a stable high-resistance basement; moreover,there are secondary paleohighs and depression structures at the lower part of the western Sichuan foreland basin with characteristic of high magnetic anomalies,whereas the Songpan-Ganzi block has a high resisitivity cover of upper crust and continues to a low-resistance *** the Longmen Mountains tectonic belt as the boundary,there are Bouguer gravity anomalies of ＂one belt between two zones.＂ Thus,we infer that there is a corresponding relation between the inferred crystalline basement of the Songpan block and the underlying basin basement of the Longmen Mountains fault ***,there may be an extensive ancient Yangtze block,which is west of the Ru

关键词： Longmen Mountains tectonic belt Wenchuan earthquake magnetotelluric sounding seismic sounding Songpan-Ganzi folded belt Qinghai-Tibet plateau

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Physics of multiple level hairpin vortex structures in turbulence

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Science China(Physics,Mechanics & Astronomy) 2016年第2期59卷 91-101页

作者： Yi Qian Wang Hassan Al-Dujaly Yong Hua Yan ning zhao Chao Qun Liu Department of Aerodynamics Nanjing University of Aeronautics and Astronautics Nanjing 210016 China Department of Mathematics University of Texas at Arlington Arlington 76019 USA

Previous experimental and numerical studies have revealed that the hairpin vortex is a basic flow element of transitional boundary layer. The hairpin vortex is believed to have legs, necks and a ring head. Based on our DNS study, the legs and the ring head are generated separately by different mechanisms. The legs function like an engine to generate low speed zones by rotation, create shear layers with surrounding high speed neighbor fluids, and further cause vortex ring formation through shear layer instability. In addition, the ring head is Ω-shaped and separated from quasi-streamwise legs from the beginning. Contrary to the classical concept of ＂vortex breakdown＂, we believe transition from laminar flow to turbulence is a ＂buildup＂ process of multiple level vortical structures. The vortex tings of first level hairpins are mostly responsible for positive spikes, which cause new vorticity rollup, second level vortex leg formation and finally smaller second level vortex ring generation. The third and lower level vortices are generated following the same mechanism. In this paper, the physical process from A-vortex to mul- ti-level hairpin vortices is described in detail.

关键词： hairpin vortex vortex buildup multiple level vortices flow transition

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Trajectory Predictions with Details in a Robotic Twin-Crane System

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Complex System Modeling and Simulation 2022年第1期2卷 1-17页

作者： ning zhao Gabriel Lodewijks Zhuorui Fu Yu Sun Yue Sun School of Mechanical Engineering University of Science and Technology BeijingBeijing 100083China School of Aviation University of New South WalesSydney 2052Australia

Nowadays,more automated or robotic twin-crane systems(RTCSs)are employed in ports and factories to improve material handling *** a twin-crane system,cranes must travel with a minimum safety distance between them to prevent *** crane trajectory prediction is critical to interference handling and crane *** trajectory predictions lack accuracy because many details are *** enhance accuracy and lessen the trajectory prediction time,a trajectory prediction approach with details(crane acceleration/deceleration,different crane velocities when loading/unloading,and trolley movement)is proposed in this *** on different details and their combinations are conducted on a container terminal case *** to the simulation results,the accuracy of the trajectory prediction can be improved by 20%.The proposed trajectory prediction approach is helpful for building a digital twin of RTCSs and enhancing crane scheduling.

关键词： twin-crane systems trajectory prediction acceleration velocity interference

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Carbazole tricationic salt:A novel potential two-photon fluorescent DNA probe for nucleic imaging of cells

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Chinese Science Bulletin 2010年第32期55卷 3661-3667页

作者： zhao ning ZHANG YuanHong LIU Xin YU XiaoQiang GE MaoFa State Key Laboratory of Crystal Materials Shandong University Jinan 250100 China Beijing National Laboratory for Molecular Sciences (BNLM) Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China

A new carbazole tricationic salt,4,4'-(1E,1'E)-2,2'-(9-(2-(1-(2-hydroxyethyl)pyridinium-4-yl)ethyl)-9H-carbazole-3,6-diyl) bis(ethane-2,1-diyl) bis(1-(2-hydroxyethyl)pyridinium) iodide (THEPC) was synthesized. Photophysical experiments have shown that THEPC has large two-photon excited fluorescence action cross-sections (33 GM in the presence of DNA),which ranks THEPC as a good biological fluorophore. The results from electronic absorption,circle dichroism and single-/two-photon fluorescence emission spectra suggest that THEPC can strongly bind to DNA,with an intrinsic binding constant of 5.79 × 106 L mol-1. THEPC has better photostability under one-or two-photon excitation conditions. Finally,the staining photos from two-photon fluorescence microscopy (TPM) show that THEPC can exclusively label the nucleus with high contrast and without image distortion. These remarkable properties and optimized imaging ability make THEPC an attractive DNA probe in TPM.

关键词：双光子激发荧光 DNA探针荧光成像咔唑核酸细胞荧光发射光谱盐

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A parallel methodology of adaptive Cartesian grid for compressible flow simulations

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Advances in Aerodynamics 2022年第1期4卷 449-478页

作者： Xinyu Qi Yuchen Yang Linlin Tian Zhenming Wang ning zhao College of Aerospace Engineering Nanjing University of Aeronautics and AstronauticsNanjing210016China State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing210016China

The combination of Cartesian grid and the adaptive mesh refinement(AMR)technology is an effective way to handle complex geometry and solve complex flow *** high-efficiency Cartesian-based AMR libraries have been developed to handle dynamic changes of the grid in parallel but still can not meet the unique requirements of simulating flow around *** this paper,we propose an efficient Cartesian grid generation method and an information transmission approach for the wall boundary to parallelize the implementation of ghost-cell method(GCM).Also,the multi-valued ghost-cell method to handle multi-value points is improved to adapt to the parallel *** the mentioned methodologies with the open-source library p4est,an automatic and efficient simulation of compressible flow is *** overall performance of the methodology is tested through a wide range of inviscid/viscous flow *** results indicate that the capability and parallel scalability of the present numerical methodology for solving multiple types of flows,involving shock and vortices,multi-body flow and unsteady flows are agreeable as compared with related reference data.

关键词： Cartesian grids AMR Parallel computing Compressible flow Immersed boundary method

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