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Nano-sized alumina supported palladium catalysts for methane combustion with excellent thermal stability

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Journal of Environmental Sciences 2023年第4期126卷 333-347页

作者： Wei Shi Guangyan Xu xuewang Han Yingjie Wang Zhi Liu Sen Xue Nannan Sun Xiaoyan Shi Yunbo Yu Hong He State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China Weichai Power Co. Ltd.Weifang 261061China Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China

Pd/Al_(2)O_(3)catalysts supported on Al_(2)O_(3)of different particle sizes were synthesized and applied in methane combustion.These catalysts were systematically characterized by Brunauer-Emmett-Teller (BET),X-ray diffraction (XRD),high resolution-transmission electron microscopy (HR-TEM),high-angle annular dark?eld-scanning transmission electron microscopy (HAADF-STEM),H_(2)-temperature-programmed reduction (H_(2)-TPR),O_(2)-temperature-programmed oxidation (O_(2)-TPO),X-ray photoelectron spectroscopy (XPS),and X-ray absorption?ne structure (XAFS).The characterization results indicated that nanosized Al_(2)O_(3)enabled the uniform dispersion of palladium nanoparticles,thus contributing to the excellent catalytic performance of these nano-sized Pd/Al_(2)O_(3)catalysts.Among them,Pd/Al_(2)O_(3)-nano-10 (Pd/Al_(2)O_(3)supported by alumina with an average particle size of 10 nm)showed superior catalytic activity and stability for methane oxidation under harsh practical conditions.It maintained excellent catalytic performance for methane oxidation for50 hr and remained stable even after harsh hydrothermal aging in 10 vol.%steam at 800℃ for 16 hr.Characterization results revealed that the strong metal-support interactions and physical barriers provided by Al_(2)O_(3)-nano-10 suppressed the coalescence ripening of palladium species,and thus contributed to the superior sintering resistance of the Pd/Al_(2)O_(3)-nano-10 catalyst.

关键词： Methane combustion Pd/Al_(2)O_(3) Hydrothermal stability Metal-support interaction Physical barriers

Integrating systematic pharmacology-based strategy and experimental validation to explore mechanism of Tripterygium glycoside on cholangiocyte-related liver injury

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Chinese Herbal Medicines 2022年第4期14卷 563-575页

作者： Yajing Li sen Li Xiaoyong xue Ting Wang Xiaojiaoyang Li School of Life Sciences Beijing University of Chinese MedicineBeijing 100029China Beijing Research Institute of Chinese Medicine Beijing University of Chinese MedicineBeijing 100029China

Objective:Tripterygium glycoside(TG)is widely used in clinical practice for its multiple bioactivities including anti-inflammatory and immunosuppressive effects.However,emerging studies have frequently reported TG-induced adverse reactions to multiple organs,especially liver.Here,this study aimed to investigate the mechanism of liver damage induced by TG and explore representative components to reflect TG hepatotoxicity.Methods:Network pharmacology was used to determine the potential targets of bile duct injury caused by TG.Next,the hepatotoxic effects of TG,triptolide(TP)and celastrol(CEL)were investigated and compared in vivo and in vitro.Liver function was determined by measuring serum transaminase and histopathology staining.The cell proliferation and apoptosis were determined by cell viability assay,scratch assay and flow cytometry.The expression of gene of interest was determined by qPCR and Western blot.Results:Based on the network pharmacological analysis of 12 bioactive ingredients found in TG,a total of35 targets and 15 pathways related to bile duct injury were obtained.Both TG and TP resulted in cholangiocyte damage and liver injury,as illustrated by increased levels of serum transaminase and oxidative stress,stimulated portal edema and lymphocytic infiltration and decreased expression of cholangiocyte marker,cytoskeletal 19.In addition,TG and TP inhibited cell proliferation and migration,arrested cell cycle and promoted Caspase-dependent apoptosis of cholangiocytes via suppressing the phosphorylation of extracellular regulated protein kinases 1/2(ERK1/2)and protein kinase B(AKT).While,CEL at equivalent dosage had no obvious hepatotoxicity.Conclusion:We revealed that TG-stimulated liver injury was specifically characterized by cholangiocyte damage and TP might be the decisive ingredient to reflect TG hepatotoxicity.Our results not only provide novel insights into the mechanism underlying the hepatotoxicity effects of TG but also offer reference for clinical rational use of TG.

关键词： cell apoptosis cholangiocyte liver injury Tripterygium glycoside triptolide

Novel SfM-DLT method for metro tunnel 3D reconstruction and Visualization

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Underground Space 2021年第2期6卷 134-141页

作者： Yadong xue sen Zhang Mingliang Zhou Hehua Zhu Key Laboratory of Geotechnical and Underground Engineering of Education Ministry Tongji UniversityShanghai 200092China Department of Geotechnical Engineering Tongji UniversityShanghai 200092China

Metro tunnels play a crucial role in urban transportation.However,with growing tunnel operation periods,defects,and large deformations appearing,these are influencing tunnel structural performance and threatening public safety.Three-dimensional(3D)tunnel reconstruction is an effective way to highlight tunnel conditions and provide a basis for engineering management and maintenance.However,the current methods of tunnel 3D reconstruction do not sufficiently combine the qualitative and quantitative characteristics of tunnel states.In this study,a novel method for metro tunnel 3D reconstruction based on structure from motion(SfM)and direct linear transformation(DLT)is proposed.The dimensionless 3D reconstruction point cloud acquired through the SfM method showcases the qualitative characteristics(such as leakage and pipelines)of the tunnel state.The close-range photogrammetry DLT method provides scale information missing from the SfM method and quantitative characteristics(such as profile deformation)of the tunnel state.The SfM-DLT method was tested in a Shanghai metro tunnel,and proved to be feasible and promising for future tunnel inspections.

关键词： Metro tunnel 3D reconstruction Visualization Structure from motion Direct linear transformation

A maximum margin clustering algorithm based on indefinite kernels

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Frontiers of Computer Science 2019年第4期13卷 813-827页

作者： Hui xue sen LI Xiaohong CHEN Yunyun WANG School of Computer Science and Engineering Southeast University Nanjing 210096 Chin Key Laboratory of Computer Network and Information Integration (Southeast University) Ministry of Education Nanjing 210096 China College of Science Nanjing University of Aeronautics and Astronautics Nanjing 210016 China Department of Computer Science and Engineering Nanjing University of Posts and Telecommunications Nanjing 210046 China

Indefinite kernels have attracted more and more attentions in machine learning due to its wider application scope than usual positive definite kernels. However, the research about indefinite kernel clustering is relatively scarce. Furthermore, existing clustering methods are mainly designed based on positive definite kernels which are incapable in indefinite kernel scenarios. In this paper, we propose a novel indefinite kernel clustering algorithm termed as indefinite kernel maximum margin clustering (IKMMC) based on the state-of-the-art maximum margin clustering (MMC) model. IKMMC tries to find a proxy positive definite kernel to approximate the original indefinite one and thus embeds a new F-norm regularizer in the objective function to measure the diversity of the two kernels, which can be further optimized by an iterative approach. Concretely, at each iteration, given a set of initial class labels, IKMMC firstly transforms the clustering problem into a classification one solved by indefinite kernel support vector machine (IKSVM) with an extra class balance constraint and then the obtained prediction labels will be used as the new input class labels at next iteration until the error rate of prediction is smaller than a prespecified tolerance. Finally, IKMMC utilizes the prediction labels at the last iteration as the expected indices of clusters.Moreover, we further extend IKMMC from binary clustering problems to more complex multi-class scenarios. Experimental results have shown the superiority of our algorithms.

关键词： indefinite kernel maximum margin clustering support vector machine kernel method

Parametric estimation for the simple linear regression model under moving extremes ranked set sampling design

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Applied Mathematics(A Journal of Chinese Universities) 2021年第2期36卷 269-277页

作者： YAO Dong-sen CHEN Wang-xue LONG Chun-xian Department of Mathematics and Statistics Jishou UniversityJishou 416000China

Cost effective sampling design is a major concern in some experiments especially when the measurement of the characteristic of interest is costly or painful or time consuming.Ranked set sampling(RSS)was first proposed by McIntyre[1952.A method for unbiased selective sampling,using ranked sets.Australian Journal of Agricultural Research 3,385-390]as an effective way to estimate the pasture mean.In the current paper,a modification of ranked set sampling called moving extremes ranked set sampling(MERSS)is considered for the best linear unbiased estimators(BLUEs)for the simple linear regression model.The BLUEs for this model under MERSS are derived.The BLUEs under MERSS are shown to be markedly more efficient for normal data when compared with the BLUEs under simple random sampling.

关键词： simple linear regression model best linear unbiased estimator simple random sampling ranked set sampling moving extremes ranked set sampling

Clinical efficacy of 595-nm pulsed-dye laser in treatment of childhood facial spider nevi: a retrospective study of 110 patients

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Chinese Medical Journal 2019年第20期132卷 2417-2422页

作者： Cheng Zhang Hong-Song Ge sen Yang xue-Jun Zhang Department of Dermatology The First Affiliated Hospital of Anhui Medical UniversityThe Key Laboratory of Dermatology(Anhui Medical University)Ministry of EducationThe Key Laboratory of Major Autoimmune DiseasesHefeiAnhui 230022China Department of Dermatology Anhui Provincial Children’s HospitalHefeiAnhui 230051China

Background:Spider nevi (SN) are quite common in children. SN are treated via different techniques, and complete removal often requires multiple treatments. However, few studies have evaluated the treatment of SN. The present study aimed to evaluate the therapeutic effect and safety of a 595-nm pulsed-dye laser (PDL) for treating facial SN in children.Methods:A total of 110 children aged 0.2 to 12 years with facial SN were treated with a 595-nm PDL in a single institution from January 2016 to February 2018. In accordance with the treatment method, the patients were retrospectively divided into the small-spot-combined-with-large-spot group (SL-group) and the large-spot group (L-group). Patients with poor therapeutic results were retreated every 6 weeks until the lesions disappeared. The minimum follow-up period was 1 year. The groups were compared using independent-samples t tests, Mann-Whitney U test, Chi-square test, and Fisher exact probability test.Results:The therapeutic efficacy was significantly higher in the SL-group than in the L-group, with clearance rates of 90.9% and 53.0% after the primary treatment, respectively (χ2= 17.937, P < 0.001). For skin lesions with a central spider body diameter ≥1 mm, the once-treatment cure rates were 100% in the SL-group and 34.8% in the L-group (χ2 = 20.780, P < 0.001). For skin lesions with a central spider body diameter <1 mm, the once-treatment cure rates were 82.6% in the SL-group and 62.8% in the L-group (χ2 = 3.961, P = 0.138). The rates of adverse reactions and recurrence did not differ between the two groups (P = 0.141 and P = 1.000, respectively).Conclusions:The 595-nm PDL might be a safe and effective treatment option for facial SN in children. The small-spot-combined-with-large-spot method is especially suitable for SN with a central spider body diameter ≥1 mm.

关键词： Lasers Telangiectasis Child Spider nevi

On comparison of modified ADRCs for nonlinear uncertain systems with time delay

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Science China(Information Sciences) 2018年第7期61卷 212-226页

作者： sen CHEN Wenchao xue Sheng ZHONG Yi HUANG Key Laboratory of Systems and Control Academy of Mathematics and Systems ScienceChinese Academy of Sciences School of Mathematical Sciences University of Chinese Academy of Sciences

To tackle systems with both uncertainties and time delays, several modified active disturbance rejection control(ADRC) methods, including delayed designed ADRC(DD-ADRC), polynomial based predictive ADRC(PP-ADRC), Smith predictor based ADRC(SP-ADRC) and predictor observer based ADRC(PO-ADRC), have been proposed in the past years. This paper is aimed at rigorously investigating the performance of these modified ADRCs, such that the improvements of each method can be demonstrated.The capability to tackle time delay, the necessity of stable open loop and the performance of rejecting uncertainties for these methods are fully studied and compared. It is proven that large time delay cannot be tolerated for the stability of the closed-loop systems based on DD-ADRC and PP-ADRC. Moreover, stable open loop is shown to be necessary for stabilizing the closed-loop systems based on SP-ADRC. Furthermore,the performance of rejecting the "total disturbance" at low frequency for these modified ADRCs is evaluated and quantitatively discussed. Finally, the simulations of a boiler turbine system illustrate the theoretical results.

关键词： extended state observer active disturbance rejection control uncertain system time delay predictor

Development of functional antibodies against influenza B virus by activation-induced cytidine deaminase in hybridoma cells

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Virologica Sinica 2022年第4期37卷 619-622页

作者： Yuanzhi Chen Chenguang Shen Jing Chen Junyu Chen Fentian Chen Limin Zhang xue Liu Siyuan Chen Sen Xue Yongliang Liu Jixian Tang Quan Yuan Yixin Chen Wenxin Luo Ningshao Xia National Institute of Diagnostics and Vaccine Development in Infectious Diseases State Key Laboratory of Molecular Vaccinology and Molecular DiagnosticsSchool of Public Health&School of Life ScienceXiamen UniversityXiamen 361102China Biosafety Level-3 Laboratory School of Public HealthSouthern Medical UniversityGuangzhou 510515China

Dear Editor,Influenza B viruses(IBVs)have circulated among humans for more than 80 years.Seasonal influenza virus epidemics caused by two IBV lines(Victoria and Yamagata)and influenza A virus have considerable effects on public health globally and result in approximately290,000–650,000 annual influenza-attributed deaths(Caini et al.,2015;Pan et al.,2015).Currently,the most effective countermeasures against influenza B virus infections are influenza virus vaccines(Subbarao and Matsuoka,2013).However,these vaccines have limited efficacy because only strain-matched humoral immune responses are induced.

关键词： influenza activation globally

Maximum Likelihood Estimator of the Location Parameter under Moving Extremes Ranked Set Sampling Design

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Acta Mathematicae Applicatae Sinica 2021年第1期37卷 101-108页

作者： Wang-xue CHEN Chun-xian LONG Rui YANG Dong-sen YAO Department of Mathematics and Statistics Jishou UniversityJishou 416000China

Cost effective sampling design is a problem of major concern in some experiments especially when the measurement of the characteristic of interest is costly or painful or time consuming.In the current paper,a modification of ranked set sampling(RSS)called moving extremes RSS(MERSS)is considered for the estimation of the location parameter for location family.A maximum likelihood estimator(MLE)of the location parameter for this family is studied and its properties are obtained.We prove that the MLE is an equivariant estimator under location transformation.In order to give more insight into the performance of MERSS with respect to(w.r.t.)simple random sampling(SRS),the asymptotic efficiency of the MLE using MERSS w.***.t.that using SRS is computed for some usual location distributions.The relative results show that the MLE using MERSS can be real competitors to the MLE using SRS.

关键词： ranked set sampling moving extremes ranked set sampling maximum Likelihood estimator equivariant estimator fisher information number