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Safety-Critical Trajectory Tracking for Mobile Robots With Guaranteed Performance

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IEEE/CAA Journal of Automatica Sinica 2024年第9期11卷 2033-2035页

作者： Wentao wu Di wu Yibo Zhang Shukang Chen Weidong Zhang Department of Automation Shanghai Jiao Tong UniversityShanghai 200240China Department of Information and Communication Engineering Hainan UniversityHaikou 570288China

Dear Editor,This letter considers a collision-free trajectory tracking problem for performance-guaranteed mobile robots(MRs)subject to *** propose a safety-critical performance-guaranteed trajectory tracking method based on control barrier functions(CBFs).First,an auxiliary system is established to generate the non-negative signals for inflexible bounds such that the performance constraints are not violated when avoiding obstacles.

关键词： constraints bounds collision

“双碳”目标下Janus In2S2X光催化还原CO_(2)的密度泛函理论研究

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化学学报 2023年第9期81卷 1148-1156页

作者：吴宇晗张栋栋尹宏宇陈正男赵文匙玉华中国石油大学(华东)材料科学与工程学院青岛266580

CO_(2)光催化还原转化为可利用的化工产品能够有效地缓解温室效应和资源短缺两大问题,有助于实现“碳达峰”和“碳中和”的伟大目标.然而由于量子效率和产物选择性等问题的影响,目前仍然无法将其大规模应用于工业生产.其中光催化剂具有... 详细信息

CO_(2)光催化还原转化为可利用的化工产品能够有效地缓解温室效应和资源短缺两大问题,有助于实现“碳达峰”和“碳中和”的伟大目标.然而由于量子效率和产物选择性等问题的影响,目前仍然无法将其大规模应用于工业生产.其中光催化剂具有关键作用.金属硫化物因具有良好的光吸收能力和带边电位,被认为是一类具有巨大应用前景的光催化剂.本工作以Janus In2S2X为基础,在表面引入了不同浓度的空位缺陷,分析了其稳定构型、电子结构以及吸收光谱.计算CO_(2)还原路径发现,空位浓度可以有效调控还原产物的选择性,具有单空位和双空位表面的催化剂分别将CO_(2)还原为HCOOH和HCHO,进一步揭示了空位浓度对催化性能的影响机理.这项工作为实验设计和制备高效的光催化剂提供了一定的理论指导.

关键词： Janus In_(2)S_(2)X 光催化空位浓度 CO_(2)还原选择性

Geometric approach to robust quantum control for time-varying noises

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Science China(Physics,Mechanics & Astronomy) 2024年第9期67卷 197-198页

作者： Rebing wu Center for Intelligent and Networked Systems Department of AutomationTsinghua UniversityBeijing 100084China

Quantum technologies are expected to revolutionze modern information processing *** all quntum technologies demand high-precision control of quantum ***,maintaining the high-precision against noises is rather difficult[1].This requirement calls for robust control pulse design that is insensitive to *** practical implementation,the control pulses need to be smoothly shaped and be able to tackle parametric uncertainties or time-varying noises with complicated frequency characteristics.

关键词： quantum smoothly shaped

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Non-alcoholic fatty liver degree and long-term risk of incident inflammatory bowel disease: A large-scale prospective cohort study

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中华医学杂志(英文版) 2024年第14期137卷 1705-1714页

作者： Zhang Qian Liu Si wu Jing Zhu Shengtao wu Yongdong wu Shanshan Zhang Shutian Department of Gastroenterology Beijing Friendship Hospital Capital Medical University National Clinical Research Center for Digestive Disease Beijing Digestive Disease Center Beijing Key Laboratory for Precancerous Lesion of Digestive Disease Beijing China

Background: Non-alcoholic fatty liver disease (NAFLD) and inflammatory bowel disease (IBD) have shown similar worsening epidemic patterns globally and shared various overlapping pathophysiological mechanisms. However, evidence on the relationship between NAFLD and IBD risk is lacking. We aimed to investigate the associations between long-term risk of incident IBD and NAFLD in a large prospective ***: Participants from the United Kingdom Biobank cohort (https://***/) who were free of IBD and alcoholic liver disease at baseline were enrolled. Baseline non-alcoholic fatty liver degree was measured by the well-established fatty liver index (FLI). The outcomes of interest included incident IBD, ulcerative colitis (UC), and Crohn’s disease (CD). Multivariable Cox proportional hazard regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).Results: Among 418,721 participants (mean FLI: 48.11 ± 30.11), 160,807 (38.40%) participants were diagnosed as NAFLD at baseline. During a median of 12.4 years’ follow-up, 2346 incident IBD cases (1545 UC, 653 CD, and 148 IBD-unclassified) were identified. Due to limited events, those IBD-unclassified were combined in UC or CD when examining the associated risk of UC or CD, separately. Compared with the lowest quartile of FLI, the highest quartile showed a separately 36.00%, 25.00%, and 58.00% higher risk of incident IBD (HRQ4vs. Q1 =1.36, 95% CI: 1.19-1.55,Ptrend <0.001), UC (HRQ4vs. Q1 =1.25, 95% CI: 1.07-1.46,Ptrend=0.047), and CD (HRQ4vs. Q1 =1.58, 95% CI: 1.26-1.97,Ptrend <0.001) after multivariable adjustment. Compared with non-NAFLD, NAFLD participants had a significantly higher risk of incident IBD (HR=1.13, 95% CI: 1.04-1.24) and CD (HR =1.36, 95% CI: 1.17-1.58).Conclusions: Higher degree of non-alcoholic fatty liver is associated with increased risk of incident IBD. Interventions aimed at improving NAFLD may be a potential targeted strategy for the detection and treatm

关键词： Non-alcoholic fatty liver disease Inflammatory bowel disease Ulcerative colitis Crohn’s disease Cohort study

Graph neural network-based scheduling for multi-UAV-enabled communications in D2D networks

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Digital Communications and Networks 2024年第1期10卷 45-52页

作者： Pei Li Lingyi Wang Wei wu Fuhui Zhou Baoyun Wang Qihui wu Nanjing University of Posts and Telecommunications Nanjing210023China Nanjing University of Aeronautics and Astronautics Nanjing210016China

In this paper,we jointly design the power control and position dispatch for Multi-Unmanned Aerial Vehicle(UAV)-enabled communication in Device-to-Device(D2D)*** objective is to maximize the total transmission rate of Downlink Users(DUs).Meanwhile,the Quality of Service(QoS)of all D2D users must be *** comprehensively considered the interference among D2D communications and downlink *** original problem is strongly non-convex,which requires high computational complexity for traditional optimization *** to make matters worse,the results are not necessarily globally *** this paper,we propose a novel Graph Neural Networks(GNN)based approach that can map the considered system into a specific graph structure and achieve the optimal solution in a low complexity ***,we first construct a GNN-based model for the proposed network,in which the transmission links and interference links are formulated as vertexes and edges,***,by taking the channel state information and the coordinates of ground users as the inputs,as well as the location of UAVs and the transmission power of all transmitters as outputs,we obtain the mapping from inputs to outputs through training the parameters of *** results verified that the way to maximize the total transmission rate of DUs can be extracted effectively via the training on ***,it also shows that the performance of proposed GNN-based method is better than that of traditional means.

关键词： Unmanned aerial vehicle D2 Dcommunication Graph neural network Power control Position planning

基于SPOC的大学英语听力有效学习模式研究

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辽宁教育行政学院学报 2020年第4期37卷 56-60页

作者：吴禹翰张宜沈阳师范大学大学外语教学部辽宁沈阳110034 沈阳师范大学研究生处辽宁沈阳110034

SPOC是一种将网络线上课程与实体线下课程相结合的新型混合式学习模式。SPOC与MOOC之间关系密切,MOOC的线上学习模式一经出现便在国内外得到广泛重视。但是,MOOC在发展过程中出现了一系列问题。SPOC混合式学习模式的出现,弥补了MOOC在... 详细信息

SPOC是一种将网络线上课程与实体线下课程相结合的新型混合式学习模式。SPOC与MOOC之间关系密切,MOOC的线上学习模式一经出现便在国内外得到广泛重视。但是,MOOC在发展过程中出现了一系列问题。SPOC混合式学习模式的出现,弥补了MOOC在发展过程的缺陷、不足等问题,从一个新的角度和新的方向入手,创新并且应用发展成为新型学习模式,可为更好地实现学习效果打下坚实基础。基于两种学习模式的分析,以期发掘构建出新型有效的大学英语听力学习模式,最终促进学生英语听力水平的提高。

关键词： SPOC 大学英语听力混合学习有效学习

Flotation separation of scheelite from calcite using luteolin as a novel depressant

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International Journal of Minerals,Metallurgy and Materials 2024年第3期31卷 462-472页

作者： Xiaokang Li Ying Zhang Haiyang He Yu wu Danyu wu Zhenhao Guan Faculty of Land and Resources Engineering Kunming University of Science and TechnologyKunming 650093China State Key Laboratory of Clean Utilization of Complex Non-Ferrous Metal Resources Kunming University of Science and TechnologyKunming 650093China

This paper proposes luteolin(LUT)as a novel depressant for the flotation-based separation of scheelite and calcite in a sodium oleate(NaOL)*** suitability of LUT as a calcite depressant is confirmed through micro-flotation *** pH=9,with LUT concentration of 50 mg·L^(-1) and NaOL concentration of 50 mg·L^(-1),scheelite recovery reaches 80.3%.Calcite,on the other hand,exhibits a recovery rate of 17.6%,indicating a significant difference in floatability between the two ***,the surface modifica-tions of scheelite and calcite following LUT treatment are characterized using adsorption capacity testing,Zeta potential analysis,Fourier transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),and atomic force microscopy(AFM).The study in-vestigates the selective depressant mechanism of LUT on *** capacity testing and Zeta potential analysis demonstrate sub-stantial absorption of LUT on the surface of calcite,impeding the further adsorption of sodium oleate,while its impact on scheelite is ***-IR and XPS analyses reveal the selective adsorption of LUT onto the surface of calcite,forming strong chemisorption bonds between the hydroxyl group and calcium ions *** directly illustrates the distinct adsorption densities of LUT on the two miner-al ***,LUT can effectively serve as a depressant for calcite,enabling the successful separation of scheelite and calcite.

关键词： scheelite calcite luteolin flotation depressant separation

Cobalt doping amount determines dominant reactive species in peroxymonosulfate activation via porous carbon catalysts co-doped by cobalt and nitrogen

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Journal of Environmental Sciences 2024年第4期138卷 212-226页

作者： Xiang Li Limeng wu Aiqin Zhang Shaohua wu Yan Lin Chunping Yang Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle Nanchang Hangkong UniversityNanchang 330063China Academy of Environmental and Resource Sciences School of Environmental Science and EngineeringGuangdong University of Petrochemical TechnologyMaoming 525000China College of Environmental Science and Engineering Hunan University and Key Laboratory of Environmental Biology and Pollution Control(Hunan University)Ministry of EducationChangsha 410082China

Switching the reaction routes in peroxymonosulfate(PMS)-based advanced oxidation processes have attracted much attention but remain ***,a series of Co-N/C catalysts with different compositions and structures were prepared by using bimetallic zeolitic imidazolate frameworks based on ZIF-8 and ZIF-67(x Zn/Co-ZIFs).Results show that Co doping amount could mediate the transformation of the activation pathway of PMS over CoN/*** Co doping amount was less than 10%,the constructed x Co-N/C/PMS system(x≤10%)was singlet oxygen-dominated reaction;however further increasing Co doping amount would lead to the generation and coexistence of sulfate radicals and high-valent cobalt,besides singlet ***,the nitrogen-coordinated Co(Co-NX)sites could serve as main catalytically active sites to generate singlet *** excess Co doping amount caused the formation of Co nanoparticles from which leached Co ions were responsible for the generation of sulfate radicals and high-valent *** to undoped N/C,Co doping could significantly enhance the catalytic *** 0.5%Co-N/C could achieve the optimum degradation(0.488 min^(-1))and mineralization abilities(78.4%)of sulfamethoxazole among the investigated Co-N/C catalysts,which was superior to most of previously reported *** addition,the application prospects of the two systems in different environmental scenarios(pH,inorganic anions and natural organic matter)were assessed and showed different degradation *** study provides a strategy to regulate the reactive species in PMS-based advanced oxidation process.

关键词： Peroxymonosulfate Sulfate radical Singlet oxygen Cobalt Zeolitic imidazolate framework Advanced oxidation process

Phase-field lattice-Boltzmann study on fully coupled thermal-solute-convection dendrite growth of Al-Cu alloy

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China Foundry 2024年第2期21卷 125-136页

作者： Yin-qi Qiu Meng-wu wu Xun-peng Qin Shou-mei Xiong Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of TechnologyWuhan 430070China Hubei Longzhong Laboratory Xiangyang 441000HubeiChina School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China

Dendrite growth is a complex liquid-solid phase transition process involving multiple physical factors.A phase-field lattice-Boltzmann method was developed to simulate the two-and three-dimension dendrite growth of Al-Cu *** effect of fully coupled thermal-solute-convection interaction on the dendrite growth was investigated by incorporating a parallel-adaptive mesh refinement algorithm into the numerical *** accurately reproducing the latent heat release,solute diffusion and convective transport behaviors at the liquidsolid interface,the interaction mechanism among thermal-solute-convection transport as well as their coupling effects on the dendrite growth dynamics were *** simulation results show that the release of latent heat slows down the dendrite growth rate,and both natural and forced convection disrupt the symmetrical growth of *** combination makes the growth of dendrites more complex,capturing important physical aspects such as recalescence,dendrite tip splitting,dendrite tilting,dendrite remelting,and solute plume in the simulation *** on the robustness and powerful ability of the numerical model,the formation mechanisms of these physical aspects were revealed.

关键词： simulation phase field dendrite growth thermal-solute-convection interaction