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Science China Mathematics 2024年第2期67卷 237-252页

作者： Hong-Lin Liao tao tang tao Zhou School of Mathematics Nanjing University of Aeronautics and AstronauticsNanjing 211106China Division of Science and Technology BNU-HKBU United International CollegeZhuhai 519087China SUSTech International Center for Mathematics Shenzhen 518055China NCMIS&LSEC Institute of Computational Mathematics and Scientific/Engineering ComputingAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China

The positive definiteness of real quadratic forms with convolution structures plays an important rolein stability analysis for time-stepping schemes for nonlocal operators. In this work, we present a novel analysistool to handle discrete convolution kernels resulting from variable-step approximations for convolution operators.More precisely, for a class of discrete convolution kernels relevant to variable-step L1-type time discretizations, weshow that the associated quadratic form is positive definite under some easy-to-check algebraic conditions. Ourproof is based on an elementary constructing strategy by using the properties of discrete orthogonal convolutionkernels and discrete complementary convolution kernels. To our knowledge, this is the first general result onsimple algebraic conditions for the positive definiteness of variable-step discrete convolution kernels. Using theunified theory, we obtain the stability for some simple nonuniform time-stepping schemes straightforwardly.

关键词： discrete convolution kernels positive definiteness variable time-stepping orthogonal convolution kernels complementary convolution kernels

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The Investigation of Data Voting Algorithm for Train air-Braking System Based on Multi-Classification SVM and ANFIS

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Chinese Journal of Electronics 2024年第1期33卷 274-281页

作者： Juhan WANG Ying GAO Yuan CAO tao tang School of Electronics and Information Engineering Beijing Jiaotong University Graduate Department China Academy of Railway Science National Engineering Research Center of Rail Transportation Operation and Control System Beijing Jiaotong University

The pressure data of the train air braking system is of great significance to accurately evaluate its operation state. In order to overcome the influence of sensor fault on the pressure data of train air braking system, it is necessary to design a set of sensor fault-tolerant voting mechanism to ensure that in the case of a pressure sensor fault, the system can accurately identify and locate the position of the faulty sensor, and estimate the fault data according to other normal data. A fault-tolerant mechanism based on multi-classification support vector machine(SVM) and adaptive network-based fuzzy inference system(ANFIS) is introduced. Multi-classification SVM is used to identify and locate the system fault state, and ANFIS is used to estimate the real data of the fault sensor. After estimation, the system will compare the real data of the fault sensor with the ANFIS estimated data. If it is similar,the system will recognize that there is a false alarm and record it. Then the paper tests the whole mechanism based on the real data. The test shows that the system can identify the fault samples and reduce the occurrence of false alarms.

关键词： Multi-classification support vector machine Adaptive network-based fuzzy inference system Train air braking system Fault-tolerant voting Multi-sensors

Enhancing single-cell encapsulation in droplet microfluidics with fine-tunable on-chip sample enrichment

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Microsystems & Nanoengineering 2024年第1期10卷 149-160页

作者： tao tang Hao Zhao Shaofei Shen Like Yang Chwee Teck Lim Department of Biomedical Engineering National University of Singapore117583 SingaporeSingapore Integrative Sciences and Engineering Programme NUS Graduate SchoolNational University of Singapore119077 SingaporeSingapore Shanxi Key Lab for Modernization of TCVM College of Life ScienceShanxi Agricultural UniversityTaiguShanxi 030801China Institute for Health Innovation&Technology National University of Singapore117599 SingaporeSingapore Mechanobiology Institute National University of Singapore117411 SingaporeSingapore Institute for Digital Molecular Analytics and Science Nanyang Technological University636921 SingaporeSingapore

Single-cell encapsulation in droplet microfluidics is commonly hindered by the tradeoff between cell suspension density and on-chip focusing performance.In this study,we introduce a novel droplet microfluidic chip to overcome this challenge.The chip comprises a double spiral focusing unit,a flow resistance-based sample enrichment module with fine-tunable outlets,and a crossflow droplet generation unit.Utilizing a low-density cell/bead suspension(2×10^(6) objects/mL),cells/beads are focused into a near-equidistant linear arrangement within the double spiral microchannel.The excess water phase is diverted while cells/beads remain focused and sequentially encapsulated in individual droplets.Focusing performance was assessed through numerical simulations and experiments at three flow rates(40,60,80μL/min),demonstrating successful focusing at 40 and 80μL/min for beads and cells,respectively.In addition,both simulation and experimental results revealed that the flow resistance at the sample enrichment module is adjustable by punching different outlets,allowing over 50%of the aqueous phase to be removed.YOLOv8n-based droplet detection algorithms realized the counting of cells/beads in droplets,statistically demonstrating single-cell and bead encapsulation rates of 72.2%and 79.2%,respectively.All the results indicate that this on-chip sample enrichment approach can be further developed and employed as a critical component in single-cell encapsulation in water-in-oil droplets.

关键词： beads outlet sample

Epigenetic silencing schlafen-11 sensitizes esophageal cancer to ATM inhibitor

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World Journal of Gastrointestinal Oncology 2024年第5期16卷 2060-2073页

作者： Jing Zhou Mei-Ying Zhang ai-ai Gao Cheng Zhu tao He James G Herman Ming-Zhou Guo School of Medicine NanKai UniversityTianjin 300071China Department of Gastroenterology and Hepatology The First Medical CenterChinese PLA General HospitalBeijing 100853China Departments of Pathology Characteristic Medical Center of The Chinese People’s Armed Police ForceTianjin 300162China The Hillman Cancer Center University of Pittsburgh Cancer InstitutePittsburghPA 15213United States National Key Laboratory of Kidney Diseases Chinese PLA General HospitalBeijing 100853China

BACKGROUND Targeting DNA damage response(DDR)pathway is a cutting-edge strategy.It has been reported that Schlafen-11(SLFN11)contributes to increase chemosensitivity by participating in DDR.However,the detailed mechanism is unclear.aiM To investigate the role of SLFN11 in DDR and the application of synthetic lethal in esophageal cancer with SLFN11 defects.METHODS To reach the purpose,eight esophageal squamous carcinoma cell lines,142 esophageal dysplasia(ED)and 1007 primary esophageal squamous cell carcinoma(ESCC)samples and various techniques were utilized,including methylationspecific polymerase chain reaction,CRISPR/Cas9 technique,Western blot,colony formation assay,and xenograft mouse model.RESULTS Methylation of SLFN11 was exhibited in 9.15%of(13/142)ED and 25.62%of primary(258/1007)ESCC cases,and its expression was regulated by promoter region methylation.SLFN11 methylation was significantly associated with tumor differentiation and tumor size(both P<0.05).However,no significant associations were observed between promoter region methylation and age,gender,smoking,alcohol consumption,TNM stage,or lymph node metastasis.Utilizing DNA damaged model induced by low dose cisplatin,SLFN11 was found to activate non-homologous end-joining and ATR/CHK1 signaling pathways,while inhibiting the ATM/CHK2 signaling pathway.Epigenetic silencing of SLFN11 was found to sensitize the ESCC cells to ATM inhibitor(AZD0156),both in vitro and in vivo.CONCLUSION SLFN11 is frequently methylated in human ESCC.Methylation of SLFN11 is sensitive marker of ATM inhibitor in ESCC.

关键词： Schlafen-11 Esophageal squamous cell carcinoma DNA methylation Synthetic lethality AZD0156

Paleogene integrative stratigraphy,biotas,and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

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Science China Earth Sciences 2024年第4期67卷 1290-1325页

作者： Jia LIU ai SONG Lin DING tao SU Zhekun ZHOU CAS Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMengla 666303China State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and PalaeontologyChinese Academy of SciencesNanjing 210008China Institute of Paleontology Yunnan UniversityKunming 650500China State Key Laboratory of Tibetan Plateau Earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China

The Paleogene is a crucial period when terrestrial and marine ecosystems recovered from major disruptions and gradually approached their modern states.In the Qinghai-Tibetan Plateau and its surrounding regions,the Paleogene also represents a significant phase of tectonic evolution in the Qinghai-Tibetan Plateau-Himalaya orogeny,reorganization of Asian climates,and evolution of biodiversity.Due to limitations in research conditions and understanding,there are still many controversies regarding stratigraphic divisions in the Qinghai-Tibetan Plateau and its surrounding regions.In recent years,extensive studies on sedimentary petrology,magnetostratigraphy,and isotope dating have been conducted in the region.Numerous fossils have been discovered and reported,contributing to a more systematic understanding of biostratigraphy.These studies have laid a solid foundation for the comprehensive investigation of the stratigraphy,biotas and paleogeographic evolution of the Qinghai-Tibetan Plateau and its surrounding regions during the Paleogene.In this paper,we integrate recent research on fossils,isotopic dating,magnetostratigraphy,and geochemistry to refine the stratigraphic divisions and correlation framework of different tectonic units in the region,building upon previous studies.Since the Second Tibetan Plateau Scientific Expedition and Research,the knowledge of Paleogene floras has gradually expanded.This paper discusses the biostratigraphic significance of extinct and newly appeared taxa based on the latest dating results of these plant species.The new understanding of fossil species such as the“Eucalyptus”and Arecaceae establishes connections between the Paleogene flora of the Qinghai-Tibetan region and the biotas of Gondwana,specifically Oceania and South America.The evolutionary history of key taxa near the Yarlung Zangbo suture zone indicates that the collision between the Indian and Eurasian plates occurred approximately 65-54 Ma.Paleoelevation reconstructions,based on plant fossils,suggest that the Hengduan Mounta

关键词： Qinghai-Tibetan Plateau Fossils Biostratigraphy Paleoenvironment Paleogeography Paleogene

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A Residual Frequency Offset Estimation Method Based on Range Migration Fitting

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Journal of Beijing Institute of Technology 2024年第2期33卷 103-110页

作者： Liting Zhang Hao Huan Ran tao Xiaogang tang School of Information and Electronics Beijing Institute of Technology School of Aerospace Information Space Engineering University

Recently, researchers have proposed an emitter localization method based on passive synthetic aperture. However, the unknown residual frequency offset(RFO) between the transmitter and the receiver causes the received Doppler signal to shift, which affects the localization accuracy. To solve this issue, this paper proposes a RFO estimation method based on range migration fitting. Due to the high frequency modulation slope of the linear frequency modulation(LFM)-modulation radar signal, it is not affected by RFO in range compression. Therefore, the azimuth time can be estimated by fitting the peak value position of the pulse compression in range direction.Then, the matched filters are designed under different RFOs. When the zero-Doppler time obtained by the matched filters is consistent with the estimated azimuth time, the given RFO is the real RFO between the transceivers. The simulation results show that the estimation error of azimuth distance does not exceed 20 m when the received signal duration is not less than 3 s, the pulse repetition frequency(PRF) of the transmitter radar signal is not less than 1 k Hz, the range detection is not larger than 1 000 km, and the signal noise ratio(SNR) is not less than –5 d B.

关键词： passive localization range migration fitting (RMF) residual frequency offset (RFO)

Machine Learning-aided Data Analysis in Single-Protein Conductance Measurement with Electron Tunneling Probes

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Chinese Journal of Chemistry 2024年第1期42卷 67-72页

作者： Yuxin Yang tao Jiang Ye Tian Biaofeng Zeng Longhua tang State Key Laboratoryof Extreme Photonics and Instrumentation College of Optical Science and EngineeringZhejiang University HangzhouZhejiang 310027China Nanhu Brain-computer Interface Institute HangzhouZhejiang 311100China State Key Laboratory of Fluid Power and Mechatronic Systems College of Mechanical EngineeringZhejiang University HangzhouZhejiang 310027China

The electrical tunneling sensors have excellent potential in the next generation of single-molecule measurement and sequencing technologies due to their high sensitivity and spatial resolution capabilities.Electrical tunneling signals that have been measured at a high sampling rate may provide detailed molecular information.Despite the extraordinarily large amount of data that has been gathered,it is still difficult to correlate signal transformations with molecular processes,which creates great obstacles for signal analysis.Machine learning is an effective tool for data analysis that is currently gaining more significance.It has demonstrated promising results when used to analyze data from single-molecule electrical measurements.In order to extract meaningful information from raw measurement data,we have combined intelligent machine learning with tunneling electrical signals.For the purpose of analyzing tunneling electrical signals,we investigated the clustering approach,which is a classic algorithm in machine learning.A clustering model was built that combines the advantages of hierarchical clustering and Gaussian mixture model clustering.Additionally,customized statistical algorithms were designed.It has been proven to efficiently gather molecular information and enhance the effectiveness of data analysis.

关键词： Tunneling sensor Single-molecule measurement Machine learning Single-protein conductance Molecular electrochemistry Nanotechnology Molecular electronics

Spatial distribution of supra-permafrost groundwater in the Qinghai-Tibet Engineering Corridor using inversion models

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Advances in Climate Change Research 2024年第1期15卷 31-41页

作者： Yu GAO Ming-tang CHai Wei MA Yu-tao GAO State Key Laboratory of Frozen Soils Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 73000China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China School of Civil and Hydraulic Engineering Ningxia UniversityYinchuan 750021China

Supra-permafrost groundwater(SPG)is a key factor that causes damage to highways and railways in the Qinghai-Tibet Engineering Corridor(QTEC).It is difficult to monitor SPG in the field due to their complex formation mechanisms and movement characteristics.Traditional single-site field monitoring studies limit the spatial and temporal precision of SPG spatial distribution.To determine the moisture content of shallow soils and the SPG distribution along the QTEC,this work employed the temperature vegetation dryness index and remote sensing models for groundwater table distribution models.The accuracies of the models were validated using mea-surements obtained from different sites in the corridor.In the permafrost zones of the QTEC,72%,22%and 6%of the SPG were located at depths of 0.5-1,1 m,respectively.Meanwhile,79.4%of the area along the Qinghai-Tibet Highway(QTH)(Xidatan-tanggula)section contained SPG.In these sections with SPG,37.9%have an SPG table at depths of 0.5-0.8 m.This study preliminarily explored the SPG distribution in the QTEC with a 30 m resolution.The findings can help improve the spatial scale of SPG research,provide a basis for the analysis of the hydrothermal mechanisms,and serve as a guide in the assessment of operational risks and road structure designs.

关键词： Dryness index Landsat Soil moisture Groundwater level Qinghai-Tibet Engineering Corridor

Effect of titanium on the sticking of pellets based on hydrogen metallurgy shaft furnace:Behavior analysis and mechanism evolution

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International Journal of Minerals,Metallurgy and Materials 2024年第2期31卷 282-291页

作者： Jinge Feng Jue tang Zichuan Zhao Mansheng Chu aijun Zheng Xiaobing Li Xiao’ai Wang School of Metallurgy Northeastern UniversityShenyang 110819China Institute for Frontier Technologies of Low-carbon Steelmaking Northeastern UniversityShenyang 110819China Liaoning Low-carbon Steelmaking Technology Engineering Research Center Northeastern UniversityShenyang 110819China Engineering Research Center of Frontier Technologies for Low-carbon Steelmaking(Ministry of Education Shenyang 110819China Zhang Xuan Technology of HBIS Group Co. Ltd.Shijiazhuang 050000China Xuanhua Iron and Steel Group Co. Ltd.Shijiazhuang 050000China Iron and Steel Research Institute of HBIS Group Co. Ltd.Shijiazhuang 050000China

Direct reduction based on hydrogen metallurgical gas-based shaft furnace is a promising technology for the efficient and low-carbon smelting of vanadium-titanium magnetite.However,in this process,the sticking of pellets occurs due to the aggregation of metal-lic iron between the contact surfaces of adjacent pellets and has a serious negative effect on the continuous operation.This paper presents a detailed experimental study of the effect of TiO2 on the sticking behavior of pellets during direct reduction under different conditions.Results showed that the sticking index(SI)decreased linearly with the increasing TiO2 addition.This phenomenon can be attributed to the increase in unreduced FeTiO3 during reduction,leading to a decrease in the number and strength of metallic iron interconnections at the sticking interface.When the TiO2 addition amount was raised from 0 to 15wt%at 1100°C,the SI also increased from 0.71%to 59.91%.The connection of the slag phase could be attributed to the sticking at a low reduction temperature,corresponding to the low sticking strength.Moreover,the interconnection of metallic iron became the dominant factor,and the SI increased sharply with the increase in re-duction temperature.TiO2 had a greater effect on SI at a high reduction temperature than at a low reduction temperature.

关键词： titanium sticking index hydrogen metallurgy direct reduction pellets

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A Layered Energy-Efficient Multi-Node Scheduling Mechanism for Large-Scale WSN

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Computers, Materials & Continua 2024年第4期79卷 1335-1351页

作者： Xue Zhao Shaojun tao Hongying tang Jiang Wang Baoqing Li Science and Technology on Microsystem Laboratory Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai200050China

In recent years, target tracking has been considered one of the most important applications of wireless sensornetwork (WSN). Optimizing target tracking performance and prolonging network lifetime are two equally criticalobjectives in this scenario. The existing mechanisms still have weaknesses in balancing the two demands. Theproposed heuristic multi-node collaborative scheduling mechanism (HMNCS) comprises cluster head (CH)election, pre-selection, and task set selectionmechanisms, where the latter two kinds of selections forma two-layerselection mechanism. The CH election innovatively introduces the movement trend of the target and establishesa scoring mechanism to determine the optimal CH, which can delay the CH rotation and thus reduce energyconsumption. The pre-selection mechanism adaptively filters out suitable nodes as the candidate task set to applyfor tracking tasks, which can reduce the application consumption and the overhead of the following task setselection. Finally, the task node selection is mathematically transformed into an optimization problem and thegenetic algorithm is adopted to form a final task set in the task set selection mechanism. Simulation results showthat HMNCS outperforms other compared mechanisms in the tracking accuracy and the network lifetime.

关键词： Node scheduling pre-selection target tracking WSN