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Green Energy & Environment 2024年第3期9卷 544-555页

作者： Hengyuan Liu xingjiang Wu Yuhao geng xin Li Jianhong Xu The State Key Laboratory of Chemical Engineering Department of Chemical EngineeringTsinghua UniversityBeijing100084China

Electrocatalytic nitrogen reduction reaction(NRR)is considered as a promising candidate to achieve ammonia synthesis because of clean electric energy,moderate reaction condition,safe operating process and harmless ***,the chemical inertness of nitrogen and poor activated capacity on catalyst surface usually produce low ammonia yield and faradic ***,the microfluidic technology is proposed to efficiently fabricate enriched iridium nanodots/carbon *** to in-situ co-precipitation reaction and microfluidic manipulation,the iridium nanodots/carbon nanomaterials possess small average size,uniform dispersion,high conductivity and abundant active sites,producing good proton activation and rapid electrons transmission and moderate adsorption/desorption *** a result,the as-prepared iridium nanodots/carbon nanomaterials realize large ammonia yield of 28.73 μg h^(-1) cm^(-2) and faradic efficiency of 9.14%in KOH ***,the high ammonia yield of 11.21 μg h^(-1) cm^(-2) and faradic efficiency of 24.30%are also achieved in H_(2)SO_(4) *** microfluidic method provides a reference for large-scale fabrication of nano-sized catalyst materials,which may accelerate the progress of electrocatalytic NRR in industrialization field.

关键词： Iridium nanodots Carbon Microfluidic technology Efficient synthesis Electrocatalytic nitrogen fixation

Intelligent Small Sample Defect Detection of Concrete Surface Using Novel Deep Learning Integrating Improved YOLOv5

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 545-547页

作者： Yongming Han lei Wang Youqing Wang Zhiqiang geng IEEE College of Information Science and Technology Beijing University of Chemical TechnologyBeijing 100029 Engineering Research Center of Intelligent PSE Ministry of Education in ChinaBeijing 100029China

Dear Editor,This letter presents an intelligent small sample defect detection of concrete surface using novel deep learning integrating the improved YOLOv5 based on the Wasserstein GAN(WGAN)enhancement *** proposed method is capable of producing top-notch data sets to address the issues of insufficient samples and substandard quality.

关键词： concrete integrating algorithm

Simulation of GaN micro-structured neutron detectors for improving electrical properties

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Chinese Physics B 2020年第2期29卷 414-419页

作者： xin-lei geng Xiao-Chuan Xia Huo-Lin Huang Zhong-Hao Sun He-Qiu Zhang xing-Zhu Cui Xiao-Hua Liang Hong-Wei Liang School of Microelectronics Dalian University of TechnologyDalian 116024China School of Optoelectronic Engineering and Instrumentation Science Dalian University of TechnologyDalian 116024China Institute of High Energy Physics Chinese Academy of Sciences(CAS)Beijing 100049China

Nowadays,the superior detection performance of semiconductor neutron detectors is a challenging *** this paper,we deal with a novel GaN micro-structured neutron detector(GaN-MSND)and compare three different methods such as the method of modulating the trench depth,the method of introducing dielectric layer and p-type inversion region to improve the width of depletion region(W).It is observed that the intensity of electric field can be modulated by scaling the trench *** the other hand,the electron blocking region is formed in the detector enveloped with a dielectric ***,the introducing of p-type inversion region produces new p/n junction,which not only promotes the further expansion of the depletion region but also reduces the intensity of electric field produced by main *** can be realized that all these methods can considerably enhance the working voltage as well as *** them,the improvement on W of GaN-MSND with the p-type inversion region is the most significant and the value of W could reach 12.8μm when the carrier concentration of p-type inversion region is 10^17 cm^-***,the value of W is observed to improve 200%for the designed GaN-MSND as compared with that without additional *** work ensures to the researchers and scientific community the fabrication of GaN-MSND having superior detection limit in the field of intense radiation.

关键词： GaN micro-structured neutron detector depletion region electric field

Dynamic motion of quadrupedal robots on challenging terrain:a kinodynamic optimization approach

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Frontiers of Mechanical Engineering 2024年第3期19卷 23-40页

作者： Qi LI lei DING xin LUO Engineering Research Center of Hubei Province for Clothing Information Wuhan 430200China School of Computer Science and Artificial Intelligence Wuhan Textile UniversityWuhan 430200China State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China

The dynamic motion of quadrupedal robots on challenging terrain generally requires elaborate spatial–temporal kinodynamic motion planning and accurate control at higher refresh rate in comparison with regular ***,conventional quadrupedal robots usually generate relatively coarse planning and employ motion replanning or reactive strategies to handle terrain *** resultant complex and computation-intensive controller may lead to nonoptimal motions or the breaking of locomotion *** this paper,a kinodynamic optimization approach is *** generate long-horizon optimal predictions of the kinematic and dynamic behavior of the quadruped robot on challenging terrain,we formulate motion planning as an optimization problem;jointly treat the foot’s locations,contact forces,and torso motions as decision variables;combine smooth motion and minimal energy consumption as the objective function;and explicitly represent feasible foothold region and friction constraints based on terrain *** track the generated motions accurately and stably,we employ a whole-body controller to compute reference position and velocity commands,which are fed forward to joint controllers of the robot’s *** verify the effectiveness of the developed approach through simulation and on a physical quadruped robot *** show that the quadruped robot can successfully traverse a 30°slope and 43% of nominal leg length high step while maintaining the rhythm of dynamic trot gait.

关键词： quadrupedal robot kinodynamic planning nonlinear optimization challenging terrain whole-body control

Controllable Ring-opening Polymerization ofδ-Valerolactone Catalyzed by Quinolinyl-Urea/MTBD Systems

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Chinese Journal of Polymer Science 2024年第8期42卷 1103-1110页

作者： xin-Yu Liu Liang Zhu Su-Yun Jie Bo-geng Li State Key Laboratory of Chemical Engineering College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310058China

Due to their excellent biocompatibility and biodegradability,aliphatic polyesters are widely used in the biomedical,packaging and agricultural fields,which are usually accessed by the ring-opening polymerization(ROP)of lactones and the catalysts particularly play an important *** a series of quinolinyl-urea catalysts have been synthesized via the reaction between isocyanate and aminoquinoline with an amino group at different substitution positions and *** combination with 7-methyl-1,5,7-triazabicyclo[4,4,0]dec-5-ene(MTBD)as a cocatalyst and benzyl alcohol(BnOH)as an initiator,1-(3,5-bis(trifluoromethyl)phenyl)-3-(quinolin-3-yl)urea(3-QU)was observed to be most active for the ROP ofδ-valerolactone(δ-VL).The polymerization conditions were optimized by varying the type of organic base,catalyst concentration and reaction *** changing the ratio of[M]_0/[I],linear polyvalerolactones(PVLs)with different molecular weights and narrow molecular weight distribution were *** kinetic and chain extension experiments were carried out to prove the"living"/controllable *** the NMR experiments were used to support the proposal of possible mechanism.

关键词： Quinolinyl-urea Ring-opening polymerization PVL

Collision-free parking recommendation based on multi-agent reinforcement learning in vehicular crowdsensing

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Digital Communications and Networks 2024年第3期10卷 609-619页

作者： xin Li xinghua lei Xiuwen Liu Hang Xiao College of Computer Science and Technology China University of Petroleum(East China)QingDao266580China

The recent proliferation of Fifth-Generation(5G)networks and Sixth-Generation(6G)networks has given rise to Vehicular Crowd Sensing(VCS)systems which solve parking collisions by effectively incentivizing vehicle ***,instead of being an isolated module,the incentive mechanism usually interacts with other *** on this,we capture this synergy and propose a Collision-free Parking Recommendation(CPR),a novel VCS system framework that integrates an incentive mechanism,a non-cooperative VCS game,and a multi-agent reinforcement learning algorithm,to derive an optimal parking strategy in real ***,we utilize an LSTM method to predict parking areas roughly for recommendations *** incentive mechanism is designed to motivate vehicle participation by considering dynamically priced parking tasks and social network *** order to cope with stochastic parking collisions,its non-cooperative VCS game further analyzes the uncertain interactions between vehicles in parking *** its multi-agent reinforcement learning algorithm models the VCS campaign as a multi-agent Markov decision process that not only derives the optimal collision-free parking strategy for each vehicle independently,but also proves that the optimal parking strategy for each vehicle is ***,numerical results demonstrate that CPR can accomplish parking tasks at a 99.7%accuracy compared with other baselines,efficiently recommending parking spaces.

关键词： Incentive mechanism Non-cooperative VCS game Multi-agent reinforcement learning Collision-free parking strategy Vehicular crowdsensing

An Approach for Human Posture Recognition Based on the Fusion PSE-CNN-BiGRU Model

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 385-408页

作者： Xianghong Cao xinyu Wang xin geng Donghui Wu Houru An School of Building and Environment Engineering Zhengzhou University of Light IndustryZhengzhou450000China

This study proposes a pose estimation-convolutional neural network-bidirectional gated recurrent unit(PSECNN-BiGRU)fusion model for human posture recognition to address low accuracy issues in abnormal posture recognition due to the loss of some feature information and the deterioration of comprehensive performance in model detection in complex home ***,the deep convolutional network is integrated with the Mediapipe framework to extract high-precision,multi-dimensional information from the key points of the human skeleton,thereby obtaining a human posture feature ***,a double-layer BiGRU algorithm is utilized to extract multi-layer,bidirectional temporal features from the human posture feature set,and a CNN network with an exponential linear unit(ELU)activation function is adopted to perform deep convolution of the feature map to extract the spatial feature of the human ***,a squeeze and excitation networks(SENet)module is introduced to adaptively learn the importance weights of each channel,enhancing the network’s focus on important ***,comparative experiments are performed on available datasets,including the public human activity recognition using smartphone dataset(UCIHAR),the public human activity recognition 70 plus dataset(HAR70PLUS),and the independently developed home abnormal behavior recognition dataset(HABRD)created by the authors’*** results show that the average accuracy of the proposed PSE-CNN-BiGRU fusion model for human posture recognition is 99.56%,89.42%,and 98.90%,respectively,which are 5.24%,5.83%,and 3.19%higher than the average accuracy of the five models proposed in the comparative literature,including CNN,GRU,and *** F1-score for abnormal posture recognition reaches 98.84%(heartache),97.18%(fall),99.6%(bellyache),and 98.27%(climbing)on the self-builtHABRDdataset,thus verifying the effectiveness,generalization,and robustness of the proposed model in enhancing human posture rec

关键词： Posture recognition mediapipe BiGRU CNN ELU attention

Realization of Quantum Secure Direct Communication with Continuous Variable

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Research 2024年第2期6卷 159-170页

作者： Zhengwen Cao Yuan Lu geng Chai Hao Yu Kexin Liang lei Wang School of Information Science and Technology Northwest UniversityXi'an710127China

With the progress of theoretical and applied technologies,the communication system based on the classical encryption is seriously threatened by quantum computing and distributed computing.A communication method that directly loads confidential information on the quantum state,quantum secure direct communication(QSDC),came into being for resisting security ***,we report the first continuous-variable QSDC(CV-QSDC)experimental demonstration for verifying the feasibility and effectiveness of the CV-QSDC protocol based on Gaussian mapping and propose a parameter estimation for signal classification under the actual *** our experiment,we provided 4×10^(2) blocks,where each block contains 105 data for direct information *** the transmission distance of 5 km in our experiment,the excess noise is 0.0035 SNU,where SNU represents the unit of shot-noise *** 4.08×10^(5) bit per second experimental results firmly demonstrated the feasibility of CV-QSDC under the fiber *** proposed grading judgment method based on parameter estimation provides a practical and available message processing scheme for CV-QSDC in a practical fiber channel and lays the groundwork for the grading reconciliation.

关键词： quantum estimation verify

High-performance Ti_(3)C_(2)T_(x)achieved by polyaniline intercalation and gelatinization as a high-energy cathode for zinc-ion capacitor

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Nano Research 2024年第6期17卷 5305-5316页

作者： Peng Liao ZiYu geng xin Zhang Wenjie Yan Zenghui Qiu Haijun Xu College of Mathematics and Physics Beijing University of Chemical TechnologyBeijing 100029China

The actual manufacture of supercapacitors(SCs)is restricted by the inadequate energy density,and the energy density of devices can be properly promoted by assembling zinc-ion capacitors(ZICs)which used capacitive cathode and battery-type ***-dimensional(2D)MXene has brought great focuses in the electrode research on the foundation of large redox-active surface,but the specific capacitance is still affected by the tight stacking of ***_(3)C_(2)T_(x)@polyaniline(PANI)heterostructures are prepared by uniformly depositing the conductive polymer PANI nanorods as the intercalation agent into the external of Ti_(3)C_(2)T_(x)nanosheets to inhibit ***,by using graphene oxide(GO)-assisted low-temperature hydrothermal self-assembly manufacture,2D heterostructures are assembled into the three-dimensional(3D)porous crosslinked Ti_(3)C_(2)T_(x)@PANI-reduced graphene oxide(RGO)*** to the synergistic work of PANI nanorods,Ti_(3)C_(2)T_(X)nanosheets,and 3D crosslinking frameworks of RGO to match capacitive and battery effects,3D porous hierarchical Ti_(3)C_(2)T_(x)@PANI-RGO heterostructure hydrogels have rich ion transport channels,a large number of active sites,and excellent reaction *** is assembled by using Ti_(3)C_(2)T_(x)@PANI-RGO heterostructure hydrogels as cathodes and zinc foil as *** this work,Ti_(3)C_(2)T_(x)@PANI-RGO//Zn ZIC exhibits a wide working window(2.0 V),marked specific capacitance(589.89 F·g^(−1)at 0.5 A·g−1),salient energy density(327.71 Wh·kg^(−1)at 513.61 W·kg^(−1)and 192.20 Wh·kg^(−1)at 13,005.87 W·kg^(−1)),and durable cycling stability(97.87%capacitance retention after 10,000 cycles at 10 A·g^(−1)).This study emphasizes the device design of ZICs and the broad prospect of Ti_(3)C_(2)T_(x)-based hydrogels as viable cathodes for ZICs.

关键词： polyaniline(PANI) Ti_(3)C_(2)T_(x)@PANI heterostructure intercalation process three-dimensional(3D)porous hydrogel high energy density zinc-ion capacitor

Understanding Urban Vitality from the Economic and Human Activities Perspective:A Case Study of Chongqing,China

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Chinese Geographical Science 2024年第1期34卷 52-66页

作者： YANG Fiona Fan LIN geng lei Yubing WANG Ying YI Zheng School of Geography and Planning Sun Yat-sen UniversityGuangzhou510006China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai519100China Chongqing Planning and Design Institute Chongqing401147China

The literature on urban vitality tends to focus on the built *** paper argues that some important processes in shaping vitality may be overlooked without examining the intensity and diversity of economic and human *** newly developed spatial big data and adopting the methods of multi-indicator measurement and spatial analysis methods,we analyzed the pattern of urban vitality in Chongqing,a provincial city in western China and,on this basis,evaluated the creation and maintenance of urban vitality from the economic and human activities *** findings indicate that the impacts of economic and human activities are positive and *** the three intensity and diversity indicators,economic intensity and population density show an effect on urban vitality stronger than that of economic ***,economic diversity has the strongest superposition or interactive effect,and is thus an important foundation *** positive effect of population density on urban vitality is largely a result of Chongqing’s jobs-housing *** case of Chongqing highlights the importance of topographic features,historical inheritance,large-scale migration,and cultural activities in shaping the distinctive vitality pattern of a *** study contends that the creation and maintenance of urban vitality can not be fully explained without incorporating the impacts of economic and human *** contributes to a comprehensive measurement of urban vitality and enriches its connotations.

关键词： urban vitality economic diversity economic intensity population density Chongqing,China