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Fixed-Time Antidisturbance Consensus Tracking for Nonlinear Multiagent Systems With Matching and Mismatching Disturbances

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IEEE/CAA Journal of Automatica Sinica 2024年第6期11卷 1410-1423页

作者： Xiangmin Tan Chunyan Hu Guanzhen Cao Qinglai Wei Wei Li Bo Han Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190 School of Aeronautics and Astronautics University of Chinese Academy of SciencesBeijing 100049China Institute of Automation Chinese Academy of SciencesBeijing 100190 School of Artificial Intelligence University of Chinese Academy of SciencesBeijing 100049China IEEE

In this paper,fixed-time consensus tracking for mul-tiagent systems(MASs)with dynamics in the form of strict feed-back affine nonlinearity is addressed.A fixed-time antidistur-bance consensus tracking protocol is proposed,which consists of a distributed fixed-time observer,a fixed-time disturbance observer,a nonsmooth antidisturbance backstepping controller,and the fixed-time stability analysis is conducted by using the Lyapunov theory correspondingly.This paper includes three main improvements.First,a distributed fixed-time observer is developed for each follower to obtain an estimate of the leader’s output by utilizing the topology of the communication network.Second,a fixed-time disturbance observer is given to estimate the lumped disturbances for feedforward compensation.Finally,a nonsmooth antidisturbance backstepping tracking controller with feedforward compensation for lumped disturbances is designed.In order to mitigate the“explosion of complexity”in the tradi-tional backstepping approach,we have implemented a modified nonsmooth command filter to enhance the performance of the closed-loop system.The simulation results show that the pro-posed method is effective.

关键词： Antidisturbance backstepping consensus tracking fixed-time stability multiagent system(MASs) strict feedback affine nonlinear systems.

Wood use and forest management by Neolithic millet farmers at the Xinglong site,northern China

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Science China Earth Sciences 2024年第6期67卷 1910-1921页

作者： Hui SHEN Zhenwei QIU Keliang ZHAO Xinying ZHOU Xiaoqiang LI Key Laboratory of Vertebrate Evolution and Human Origins Institute of Vertebrate Paleontology and PaleoanthropologyChinese Academy of SciencesBeijing 100044China national Museum of China Beijing 100006China University of chinese academy of Sciences Beijing 100049China

The origin and development of agriculture and its relationship with climate change are hotly debated topics among environmental archaeologists.In this study,we analyzed wood charcoal materials from the Neolithic Xinglong site in northern China in order to understand the woody vegetation around the site and how early millet farmers shaped local woodlands.Our results suggest that the area around the Xinglong sites during 8700-7000 yr BP was primarily woodlands,including Prunus sibirica shrubs,Ulmus and Acer forests,and Populus stands near waterways.From 8000 to 7000 yr BP,the warm and humid climate probably contributed to the expansion of Acer,Rhamnus,and Juniperus,and may have facilitated the development of early millet agriculture.Among these ancient wood fragments that we studied,the high percent of Prunus charcoal appears to indicate an abundance of fruit trees,which might have constituted the main component of local vegetation.Meanwhile,the wood taxa illustrate the existence of a variety of ecological habitats,and it is logical to assume that people made full use of the locally available wood resources.Notably,Populus and Ulmus were the dominant sources of fuel.The results of tree-ring curvature analyses indicate that people mainly collected trunks or large branches of Ulmus,Populus,Acer,and Juniperus timbers.We interpret the increasing use of Prunus twigs and the declining percentage of Prunus charcoal in the period between 8000-7000 yr BP as indicating that people started to protect and manage wild fruit trees.They may have started pruning to acquire more food resources as part of the cultural responses and adaptation strategies employed by these early millet cultivators.

关键词： Xinglong site Wood charcoal Wood use Woodland management

Fiducial Approach for the Storage Reliability Assessment of Complex Repairable Systems

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Journal of Systems Science & Complexity 2024年第4期37卷 1653-1671页

作者： YANG Yang ZHAO Letian CHEN Siyi YU Dan University of chinese academy of Sciences Computer Application Institute of Nuclear Industry academy of Mathematics and Systems Science Chinese Academy of Sciences

In recent years, there has been a growing focus on high-reliability products in industrial and military fields. Storage plays a crucial role in these products, and as a result, research on storage reliability has gained more attention. This paper specifically targets a class of products with complex structures that require long-term storage, regular testing, and maintenance. Firstly, an expression method for system availability is provided based on the reliability structure of the system and the maintenance situation of the constituent equipment in storage. Since the expression of system availability is typically complex and difficult to compute, and the storage life of the system cannot be represented as an explicit function of the reliability indicators of the constituent equipment, it is challenging to evaluate the availability and storage life of repairable systems. To address this, the paper proposes a comprehensive evaluation methodology for assessing the storage reliability of complex repairable systems based on fiducial inference. This approach is employed to derive point estimates and determine the lower fiducial limits for both system availability and storage life. Furthermore, simulation results demonstrate that this comprehensive evaluation method for storage reliability of complex repairable systems is not only convenient but also highly effective.

关键词： Availability fiducial method repairable system storage life

Bioprinting of inorganic-biomaterial/neural-stem-cell constructs for multiple tissue regeneration and functional recovery

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national Science Review 2024年第4期11卷 228-244页

作者： Hongjian Zhang Chen Qin Zhe Shi Jianmin Xue Jianxin Hao Jinzhou Huang Lin Du Hongxu Lu Chengtie Wu State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of Ceramics Chinese Academy of Sciences Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences

Tissue regeneration is a complicated process that relies on the coordinated effort of the nervous, vascular and immune systems. While the nervous system plays a crucial role in tissue regeneration, current tissue engineering approaches mainly focus on restoring the function of injury-related cells, neglecting the guidance provided by nerves. This has led to unsatisfactory therapeutic outcomes. Herein, we propose a new generation of engineered neural constructs from the perspective of neural induction, which offers a versatile platform for promoting multiple tissue regeneration. Specifically, neural constructs consist of inorganic biomaterials and neural stem cells(NSCs), where the inorganic biomaterials endows NSCs with enhanced biological activities including proliferation and neural differentiation. Through animal experiments, we show the effectiveness of neural constructs in repairing central nervous system injuries with function recovery. More importantly, neural constructs also stimulate osteogenesis, angiogenesis and neuromuscular junction formation, thus promoting the regeneration of bone and skeletal muscle, exhibiting its versatile therapeutic performance. These findings suggest that the inorganic-biomaterial/NSC-based neural platform represents a promising avenue for inducing the regeneration and function recovery of varying tissues and organs.

关键词： 3D bioprinting neural stem cells inorganic biomaterials neural constructs multiple tissue regeneration

Flame Synthesis of Zr/ZSM-5 Catalysts with Tunable Acidity for the Oxidative Dehydrogenation of Propane to Propene

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Journal of Thermal Science 2024年第1期33卷 268-283页

作者： DANIEL Samuel FONZEU MONGUEN Cedric Karel WU Lingnan TIAN Zhenyu Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of chinese academy of Sciences Beijing 100049China

Tuning the surface acidity of ZSM-5 catalyst is essential to achieve desired propene selectivity and yield.Here several ratios of Zr were utilized to modify ZSM-5 via flame spray pyrolysis technique coupled with a pulse spray evaporation system.The interaction between Zr and ZSM-5 in the flame influenced the physicochemical and acidity properties of the Zr/ZSM-5.The increasing Zr ratio in ZSM-5 shows coated layers of irregular nano-sized Zr with an increase in crystallite sizes due to the synergetic effect between Zr and ZSM-5.The surface chemical analysis revealed increased lattice oxygen on the Zr modified ZSM-5(1:4) sample compared to other catalysts.The acidity analysis revealed the Lewis and Br?nsted acid distribution in the weak and medium acid sites on the catalyst surface.However,the increase in Zr loading decreased the concentration of Br?nsted acid sites and tuned the catalyst surface to more Lewis acidity,promoting propene selectivity and hindering the over-oxidation of propene.The modified ZSM-5 catalysts were examined in a fixed bed reactor within 300℃-700℃ at a gas hourly space velocity(GHSV) of 6000 mL·g(catalysts)^(-1)·h^(-1) for the oxidative dehydrogenation of propane(ODHP) to propene.Among the catalysts,Zr/ZSM-5(1:4) exhibited the best propene yield, with 57.19% propane conversion and 75.54% selectivity to propene and the highest stability.This work provides a promising strategy for tuning the surface acidity of ZSM-5 with Zr for ODHP applications.

关键词： flame synthesis Zr modified ZSM-5 catalyst ODHP surface acidity lattice oxygen

Development and validation of a model integrating clinical and coronary lesion-based functional assessment for longterm risk prediction in PCI patients

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Journal of Geriatric Cardiology 2024年第1期21卷 44-63页

作者： Shao-Yu WU Rui ZHANG Sheng YUAN Zhong-Xing CAI Chang-Dong GUAN Tong-Qiang ZOU Li-Hua XIE Ke-Fei DOU State Key Laboratory of Cardiovascular Disease BeijingChina Cardiometabolic Medicine Center Fu Wai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina Catheterization Laboratories Fu Wai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina Department of Cardiology Fu Wai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina

OBJECTIVES To establish a scoring system combining the ACEF score and the quantitative blood flow ratio(QFR) to improve the long-term risk prediction of patients undergoing percutaneous coronary intervention(PCI).METHODS In this population-based cohort study, a total of 46 features, including patient clinical and coronary lesion characteristics, were assessed for analysis through machine learning models. The ACEF-QFR scoring system was developed using 1263consecutive cases of CAD patients after PCI in PANDA Ⅲ trial database. The newly developed score was then validated on the other remaining 542 patients in the cohort.RESULTS In both the Random Forest Model and the Deep Surv Model, age, renal function(creatinine), cardiac function(LVEF)and post-PCI coronary physiological index(QFR) were identified and confirmed to be significant predictive factors for 2-year adverse cardiac events. The ACEF-QFR score was constructed based on the developmental dataset and computed as age(years)/EF(%) + 1(if creatinine ≥ 2.0 mg/d L) + 1(if post-PCI QFR ≤ 0.92). The performance of the ACEF-QFR scoring system was preliminarily evaluated in the developmental dataset, and then further explored in the validation dataset. The ACEF-QFR score showed superior discrimination(C-statistic = 0.651;95% CI: 0.611-0.691, P < 0.05 versus post-PCI physiological index and other commonly used risk scores) and excellent calibration(Hosmer–Lemeshow χ^(2)= 7.070;P = 0.529) for predicting 2-year patient-oriented composite endpoint(POCE). The good prognostic value of the ACEF-QFR score was further validated by multivariable Cox regression and Kaplan–Meier analysis(adjusted HR = 1.89;95% CI: 1.18–3.04;log-rank P < 0.01) after stratified the patients into high-risk group and low-risk group.CONCLUSIONS An improved scoring system combining clinical and coronary lesion-based functional variables(ACEF-QFR)was developed, and its ability for prognostic prediction in patients with PCI was further validated to be significantly better than the post-PCI physiological

关键词： patients coronary prediction

Unraveling the stereoscopic gene transcriptional landscape of zebrafish using Fish SED,a fish spatial expression database with multispecies scalability

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Science China(Life Sciences) 2024年第4期67卷 843-846页

作者： Cheng Guo Weidong Ye Danying Cao Mijuan Shi Wanting Zhang Yingyin Cheng Yaping Wang Xiao-Qin Xia Institute of Hydrobiology Chinese Academy of SciencesWuhan 430072China College of Advanced Agricultural Sciences University of Chinese Academy of SciencesBeijingChina The Innovative academy of Seed Design Chinese Academy of SciencesBeijing 100101China

Dear Editor,The expression profile demonstrates how each gene was expressed in the target tissue or cell at a given time.Cell heterogeneity is a biological concept characterized by the presence of numerous cells with varying functions and expression profiles within organ/tissue samples.There is also cell-to-cell signaling,which implies that the extracellular environment and spatial location influence intracellular transcription,resulting in spatial heterogeneity of gene expression within the same cell type.

关键词： landscape fish database

Two methods for separating the magnetospheric solar wind charge exchange soft X-ray emission from the diffuse X-ray background

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Earth and Planetary Physics 2024年第1期8卷 119-132页

作者： YingJie Zhang TianRan Sun JenniferACarter WenHao Liu Steve Sembay ShuiNai Zhang Li Ji Chi Wang State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China College of Earth and Planetary Sciences The University of Chinese Academy of SciencesBeijing 100190China School of Physics and Astronomy The University of LeicesterLeicesterUK Purple Mountain Observatory Chinese Academy of SciencesNanjing 210008China

Solar wind charge exchange(SWCX)is the process of solar wind high-valence ions exchanging charges with neutral components and generating soft X-rays.Recently,detecting the SWCX emission from the magnetosphere is proposed as a new technique to study the magnetosphere using panoramic soft X-ray imaging.To better prepare for the data analysis of upcoming magnetospheric soft X-ray imaging missions,this paper compares the magnetospheric SWCX emission obtained by two methods in an XMM-Newton observation,during which the solar wind changed dramatically.The two methods differ in the data used to fit the diffuse X-ray background(DXB)parameters in spectral analysis.The method adding data from the ROSAT All-Sky Survey(RASS)is called the RASS method.The method using the quiet observation data is called the Quiet method,where quiet observations usually refer to observations made by the same satellite with the same target but under weaker solar wind conditions.Results show that the spectral compositions of magnetospheric SWCX emission obtained by the two methods are very similar,and the changes in intensity over time are highly consistent,although the intensity obtained by the RASS method is about 2.68±0.56 keV cm^(-2)s^(-1)sr^(-1)higher than that obtained by the Quiet method.Since the DXB intensity obtained by the RASS method is about 2.84±0.74 keV cm^(-2)s^(-1)sr^(-1)lower than that obtained by the Quiet method,and the linear correlation coefficient between the difference of SWCX and DXB obtained by the two methods in diffe rent energy band is close to-1,the diffe rences in magnetospheric SWCX can be fully attributed to the diffe rences in the fitted DXB.The difference between the two methods is most significant when the energy is less than 0.7 keV,which is also the main energy band of SWCX emission.In addition,the difference between the two methods is not related to the SWCX intensity and,to some extent,to solar wind conditions,because SWCX intensity typically va ries with the solar wind.In summary,both methods are robust a

关键词： solar wind charge exchange(SWCX) ROSAT All-Sky Survey(RASS) soft X-ray X-ray imaging magnetosphere

FL-Online:An x-ray crystallographic web-server for atomic-scale structure analysis of biomolecule

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chinese Physics B 2024年第7期33卷 37-42页

作者：王宾堂牛彤欣范海福丁玮 Beijing national Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China University of chinese academy of Sciences Beijing 100049China Songshan Lake Materials Laboratory Dongguan 523808China Center for Biological Imaging Core Facilities for Protein ScienceInstitute of BiophysicsChinese Academy of SciencesBeijing 100101China

FL-Online(http://***) is an out-of-box modern web service featuring a user-friendly interface and simplified parameters, providing academic users with access to a series of online programs for biomolecular crystallography, including SAPI-online, OASIS-online, C-IPCAS-online and a series of upcoming software releases. Meanwhile, it is a highly scalable and maintainable web application framework that provides a powerful and flexible solution for academic web development needs. All the codes are open-source under MIT licenses in GitHub.

关键词： graphical web service OASIS IPCAS direct methods protein crystallography