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When the orbital degree of freedom meets higher-order topology

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Light(Science & Applications) 2023年第5期12卷 706-707页

作者： jiazheng Li Meng Xiao Key Laboratory of Artificial Micro-and Nano-structures of Ministry of Education and School of Physics and Technology Wuhan UniversityWuhan 430072China Wuhan Institute of Quantum Technology Wuhan 430206China

The orbital degree of freedom(ODoF),which has a significant impact on exotic quantum states of matter and solidstate materials,has now been combined with higher-order *** experimental realization of a photonic p-orbital higher-order topological insulator can lead to exploring a wide range of novel topological phases involving the ODoF.

关键词： orbital topological topology

Comparison of life cycle assessment of large-scale biogas projects with different raw materials in China

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International Journal of Agricultural and Biological Engineering 2024年第2期17卷 268-279页

作者： jiazheng Sun Youpei Qu Xiaoyi lyu Xinjie Ding Xinying Miao Mukesh Kumar Awasthi Jingbo Qu School of Energy and Environment City University of Hong KongHong Kong 999077China College of Engineering Northeast Agricultural UniversityHarbin 150030China Key Laboratory of Agricultural Renewable Resources Utilization Technology and Equipment in Cold Areas of Heilongjiang Province Harbin 150030China College of Natural Resources and Environment Northwest A&F UniversityYangling 712100Shaanxi China

The anaerobic digestion(AD)disposal of stover and cattle manure is of great significance to the development of low-carbon economy and green energy in China,but it will also have an impact on the environment,and the degree of influence is different for various raw *** this study,life cycle assessment(LCA)methods were applied to analyze and compare the impact of corn stovers biogas projects(CSBP)and dairy manure biogas projects(DMBP)on the environment during the whole operation *** results of inventory analysis were evaluated by ReCiPe2016 Hierarchy(H)mid-point(problem-oriented)and end-point(destruction-oriented)method,*** results showed that the net energy efficiency of CSBP was higher(763.903 kW·h/FU)and the greenhouse gas(GHG)emission reduction of DMBP was more(5541.418 kg CO_(2)-eq/FU).The anaerobic digestion(AD)units have the greatest environmental impacts,and human carcinogenic toxicity is the largest environmental impact category(1.16-1.43 PE).The key to reducing environmental impact is reducing the input of chemical substances and the waste of electric *** CSBP and DMBP have a favorable impact on ecosystem quality and resources,and CSBP is more beneficial to the environment(-10.297 Pt).Co-digestion is an important measure to reduce the environmental damage from biogas *** research results provide theoretical support for the selection of raw materials for large-scale biogas projects in China,provide technical basis for reducing the impact of actual operation on the environment,and promote the resource utilization of agricultural waste and carbon dioxide emission reduction and sequestration.

关键词： life cycle assessment environmental impact assessment large-scale biogas projects bioenergy carbon dioxide emission reduction

Undrained vane shear strength of sand-foam mixtures subjected to different shear rates

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第6期15卷 1591-1602页

作者： jiazheng Zhong Shuying Wang Tongming Qu School of Civil Engineering Central South UniversityChangsha410075China Tunnel and Underground Engineering Research Center Central South UniversityChangsha410075China Department of Civil and Environmental Engineering The Hong Kong University of Science and TechnologyClearwater BayHong KongChina

The shear strength of sand-foam mixtures plays a crucial role in ensuring successful earth pressure balance(EPB)shield *** the sand-foam mixtures are constantly sheared by the cutterhead and the screw conveyor with varied rotation speeds during tunneling,it is non-trivial to investigate the effect of shear rates on the undrained shear strength of sand-foam mixtures under chamber pressures to extend the understanding on the tunneling *** study conducted a series of pressurized vane shear tests to investigate the role of shear rates on the peak and residual strengths of sand-foam mixtures at different pore *** from the shear-rate characteristics of natural sands or clay,the results showed that the peak strength of sand-foam mixtures under high vertical total stress(σ_(v)≥200 kPa)and low foam injection ratio(FIR30%)decreased with the increase in shear ***,the peak strength was not measurably affected by shear *** sand-foam mixtures in the residual state resembled low-viscous fluid with yield stress and the residual strength increased slightly with shear *** addition,the peak and residual strengths were approximately linear with vertical effective stress regardless of the total stress and *** peak effective internal friction angle remained almost invariant in a low shear rate(γ′<0.25 s1)but decreased when the shear rate continued *** residual effective internal friction angle was lower than the peak counterpart and insensitive to shear *** study unveiled the role of shear rates in the undrained shear strength of sand-foam mixtures with various FIRs and vertical total *** findings can extend the understanding of the rate-dependent shear characteristics of conditioned soils and guide the decision-making of soil conditioning schemes in the EPB shield tunneling practice.

关键词： Sand-foam mixture Shear rate Peak and residual strengths Effective stress Effective internal friction angle

Fuzzy energy management strategy for parallel HEV based on pigeon-inspired optimization algorithm

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Science China(Technological Sciences) 2017年第3期60卷 425-433页

作者： PEI jiazheng SU YiXin ZHANG DanHong School of Automation Wuhan University of Technology Wuhan 430070 China

Improvements in fuel consumption and emissions of hybrid electric vehicle(HEV)heavily depend upon an efficient energy management strategy(EMS).This paper presents an optimizing fuzzy control strategy of parallel hybri... 详细信息

关键词： parallel hybrid electric vehicles(parallel HEV) energy management strategy(EMS) fuzzy controller pigeon-inspired optimization(PIO) algorithm quantum evolution chaotic search

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Independent continuous mapping for topological optimization of frame structures

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Acta Mechanica Sinica 2006年第6期22卷 611-619页

作者： Yunkang Sui jiazheng Du Yingqiao Guo Department of Mechanics Beijing University of Technology Beijing 100022 China Lab. GMMS University of Reims Champagne-Ardenne BP1039 51687 Reims France

Based on the Independent Continuous Mapping method （ICM）, a topological optimization model with continuous topological variables is built by introducing three filter functions for element weight, element allowable stress and element stiffness, which transform the 0-1 type discrete topological variables into continuous topological variables between 0 and 1. Two methods for the filter functions are adopted to avoid the structural singularity and recover falsely deleted elements： the weak material element method and the tiny section element method. Three criteria （no structural singularity, no violated constraints and no change of structural weight） are introduced to judge iteration convergence. These criteria allow finding an appropriate threshold by adjusting a discount factor in the iteration procedure. To improve the efficiency, the original optimization model is transformed into a dual problem according to the dual theory and solved in its dual space. By using MSC/Nastran as the structural solver and MSC/Patran as the developing platform, a topological optimization software of frame structures is accomplished. Numerical examples show that the ICM method is very efficient for the topological optimization of frame structures.

关键词： Frame structures Topological optimization ICM method Filter functions Element elimination

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Traffic Sign Recognition Using an Attentive Context Region-Based Detection Framework

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Chinese Journal of Electronics 2021年第6期30卷 1080-1086页

作者： LIU Zhigang DU Juan TIAN Feng WEN jiazheng School of Computer and Information Technology Northeast Petroleum University Postdoctoral Workstation on Applied Technology Research Institute Northeast Petroleum University Department of Computer Science for Artificial Intelligence University of Nottingham Ningbo

Accurate small traffic sign recognition is more important for the safety of intelligent transportation systems. A recognition framework named attentive context region-based detection framework(AC-RDF) is proposed in this paper. We construct the attentive context feature for the recognition of small traffic signs,which combines the target information and the contextual information by the concatenation operation following a pointwise convolutional layer. The proposed attentive context feature exploits the surrounding information for a given object proposal. Next, we propose a novel attentive loss function to replace the original crossentropy function. It distinguishes hard negative samples from easy positive ones in the total loss, allows the proposed framework to obtain enough training, and further improve the recognition accuracy. The proposed method is evaluated on the challenging Tsinghua-Tencent 100 K dataset. The experimental results indicate that the attentive context region-based detection framework is superior at detecting small traffic signs and achieves stateof-the-art performance compared with other methods.

关键词： attentive context region-based detection framework intelligent transportation systems convolutional neural nets attentive context feature AC-RDF framework attentive loss function traffic signs learning (artificial intelligence) Tsinghua-Tencent 100K dataset object recognition feature extraction traffic sign recognition object detection entropy recognition framework

Topology optimization of continuum structures considering damage based on independent continuous mapping method

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Acta Mechanica Sinica 2019年第2期35卷 433-444页

作者： jiazheng Du Yunhang Guo Zuming Chen Yunkang Sui College of Mechanical Engineering and Applied Electronics Technology Beijing University of Technology Beijing 100124 China

A continuum topology optimization usually produces results similar to a skeleton structure. In addition, the material utilization in the optimized structure is greatly improved compared with the original structure. On the other hand, the redundancy of the structure is greatly reduced due to the removed material. A partial local failure in the optimized structure makes it more difficult for the entire structure to meet the strength/stiffness requirements. By using the independent continuous mapping (ICM) method, with minimal weight as the objective and both stress and displacement as the respective constraints, the continuum topology optimization models can be employed, which also consider damage. A dual-sequence quadratic programming (DSQP) algorithm is used to solve the topology optimization models. Numerical examples confirm the effectiveness and feasibility of the models. The results indicate that both a good load-path and weight reduction can be obtained. In addition, compared with the structure obtained using conventional topology optimization, redundancy is improved greatly, and the strength/stiffness requirements for the structure can be satisfied for each damage scenario. Furthermore, the results indicate that the strength/stiffness of the structure, after topology optimization, is slightly sensitive for local damage.

关键词： Damage Redundancy Topology optimization ICM method

Dealloying induced nanoporosity evolution of less noble metals in Mg ion batteries

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Journal of Magnesium and Alloys 2021年第6期9卷 2122-2132页

作者： jiazheng Niu Meijia Song Ying Zhang Zhonghua Zhang Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials(Ministry of Education) School of Materials Science and EngineeringShandong UniversityJingshi Road 17923Jinan 250061P.R.China

Rechargeable Mg ion batteries(MIBs)have aroused great interests,and using alloy-type anodes and conventional electrolytes offers an effective way to develop high energy density Mg battery ***,the dealloying-induced nanoporosity evolution of alloy-type anodes during the charging process has received less ***,using a magnetron-sputtered Mg;Bi;film as an example,we investigate its electrochemical dealloying and associated structural evolution in an all-phenyl-complex electrolyte by in-situ and ex-situ *** microstructures and length scales of nanoporous Bi can be facilely regulated by changing electrochemical parameters,and there exists a good linear correlation between the surface diffusivity of Bi and the applied current density/potential scan rate on a logarithm *** importantly,the self-supporting nanoporous Bi electrodes deliver satisfactory Mg storage performance and alloy-type anodes show good compatibility with conventional ***,the charging-induced dealloying in MIBs is a general strategy to fabricate nanoporous less noble metals like Sn,Pb,In,Cu,Zn and Al,which shows advantages over chemical dealloying in aqueous *** findings highlight the significance of nanoporosity evolution of alloy-type anodes during dealloying,and open opportunities for the fabrication of nanoporous reactive metals.

关键词： Mg ion batteries Alloy-type anodes Dealloying Nanoporous metals Surface diffusivity

Topology Optimization of Strength-Safe Continuum Structures Considering Random Damage

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Computer Modeling in Engineering & Sciences 2023年第8期136卷 1091-1120页

作者： jiazheng Du Xue Cong Ying Zhang Beijing University of Technology Beijing10005China

Spacecraft in the aerospace field and military equipment in the military field are at risk of being impacted by external objects,which can cause local damage to the *** randomness of local damage is a newchallenge for structural design,and it is essential to take random damage into account in the conceptual design phase for the purpose of improving structure’s resistance to external *** this article,a random damaged structure is assumed to have damages of the same size and shape at random locations,and the random damage is considered as multiple damage conditions of the *** order to improve the randomness and comprehensiveness of the multiple damage conditions,the stacking strategy is used to generate the distribution of the damage *** this strategy,the topology optimization design of the random damaged structure,which is to minimize the weight of the structure with a constraint on the stress of the structure under multiple damage conditions,is formulated based on the independent continuousmapping(ICM)*** dual sequence quadratic programming(DSQP)algorithm combined with the stress globalization method is adopted to solve the optimization *** numerical examples demonstrate the effectiveness and applicability of the proposed method in the topology optimization of strength-safe continuum structures.

关键词： Random damage-safety design topology optimization ICM method stacking strategy