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Photocatalytic performance and dispersion stability of nanodispersed TiO2 hydrosol in electrolyte solutions with different cations

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Journal of Environmental Sciences 2020年第2期32卷 59-71页

作者： Zixiao Wang PAN Feng Heng Chen Qingliang Yu Jiangsu Key Laboratory of Construction Materials School of Materials Science and EngineeringSoutheast UniversityNanjing 211189China Department of the Built Environment Eindhoven University of Technology5600 MB Eindhoventhe Netherlands School of Civil Engineering Wuhan UniversityWuhan 430072China State Key Laboratory of High Performance Civil Engineering Materials Nanjing 210008China

The existence of electrolytes in aquatic environment on the photocatalytic performance and coagulation of nanodispersed TiO2 hydrosol and the corresponding photocatalytic alteration were investigated by studying cations(Na^+, K^+, Ca^2+, Mg^2+, and Al^3+).The photocatalysis reactions of nano TiO2 with different dosages of electrolytes were measured by monitoring the degradation of Rhodamine B(Rh B) under ultraviolet A(UV-A) irradiation over time.The results showed that the photocatalytic performance of TiO2 was improved by the presence of Al^3+, while the performance was impaired by the other tested cations.The negative influences of divalent ions on the photocatalytic performance of TiO2 were more significant than monovalent ions.The TiO2 sol dispersed stable at nano scale at low concentration of electrolyte( 0.1 mol/L) with larger increase or decrease of pH.The positive effects of Al^3+on the photodegradation rate of Rh B might relate to the strong hydrolytic action of Al^3+in aquatic solutions.The photocatalytic processes of TiO2 in the presence of all ions followed the Langmuir-Hinshelwood model, and the reaction kinetic constant was increased with the decrease of pH caused by different cations.These work suggested a new perspective about the relationship between coagulation and photocatalytic performance of TiO2 hydrosols in electrolyte with hydrolysable cations, which demonstrated that TiO2 hydrosols may be suitable as photocatalysts in aquatic environments.

关键词： Photocatalytic oxidation Nano dispersed TiO2 hydrosol Aqueous inorganic cations Stability Photocatalytic kinetic

Automatic video mosaicking algorithm via dynamic key-frame

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Journal of Systems Engineering and Electronics 2020年第2期31卷 272-278页

作者： JI Yufeng LI Weixing feng Kai XING Boyang PAN Feng School of Automation Beijing Institute of TechnologyBeijing 100081China Kunming-BIT Industry Technology Research Institute Co. LtdKunming 650106China

Automatic video mosaicking is a challenging task in computer vision. Current researches consider either panoramic or mapping tasks on short videos. In this paper, an automatic mosaicking algorithm is proposed for both mapping and panoramic tasks based on the adapted key-frame on videos of any length.The speeded up robust features(SURF) and the grid motion statistic(GMS) algorithm are used for feature extraction and matching between consecutive frames, which are used to compute the transformation. In order to reduce the influence of the accumulated error during image stitching, an evaluation metric is put forward for the transformation matrix. Besides, a self-growth method is employed to stitch the global image for long videos. The algorithm is evaluated by using aerial-view and panoramic videos respectively on the graphic processing unit(GPU) device, which can satisfy the real-time requirement. The experimental results demonstrate that the proposed algorithm is able to achieve a better performance than the state-of-art.

关键词： video mosaicking image stitching speeded up robust feature(SURF) panorama mapping

Fault Detection of Networked Control System subject to Random Packet Dropout and Multi-Rate Sample Data

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Fault Detection of Networked Control System subject to Rando...

Joint parameter and state estimation for stochastic uncertain system with multivariate skew t noises

第36届中国控制会议

作者： feng Xiaoxue PAN Feng Li Shuhui School of Automation Beijing Institute of Technology

ISBN: (纸本)9781538629185

In this paper,the problem of fault detection is addressed for networked control system（NCS） subject to both random packet dropout and multi-rate sampled data,which is usually unavoidable.Since the networked control system suffers heavy resources competition and network congestion under the limited bandwidth,resulting in multi-rate sampling and data packet dropout.Observer based residual generation and evaluation approach is proposed.First,by lifting the multi-rate multi-sensor model to a single-rate one,a residual generator with causality constraint is obtained.Then,the parameters of the residual generator are achieved by optimizing a performance index,which is robust to the unknown disturbances and packet dropout without loss of the sensitivity to the faults.Finally,an appropriate threshold of residual evaluation is calculated by making full use of the stochastic properties of the disturbances.Simulation results are given to illustrate the effectiveness of the proposed method.

关键词： Fault detection Residual generation Residual evaluation Packet dropout Multi-rate sensors

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Chinese Journal of Aeronautics 2022年第5期35卷 69-86页

作者： Shuhui LI Zhihong DENG Xiaoxue feng Ruxuan HE feng pan School of Automation Beijing Institute of TechnologyBeijing 100081China Kunming-BIT Industry Technology Research Institute INC Kunming 650106China

Due to the pulse interference, measurement outliers and artificial modeling errors, the multivariate skew t noise widely exists in the real environment. However, to date, little attention has been paid to the state estimation for systems in which the process noise and the measurement noise are both modeled as the heavy-tailed and skew non-Gaussian noise. In this paper, the multivariate skew t distribution is utilized to model the heavy-tailed and skew non-Gaussian noise. Then a probabilistic graphical form of the multivariate skew t distribution is given and proved. Based on the probabilistic graphical form, a hierarchical Gaussian state space model for stochastic uncertain systems is proposed, which transforms the estimation problem for systems with the heavy-tailed and skew non-Gaussian noises into the one with a hierarchical Gaussian state space model. Next, given the designed Gaussian state space model, the robust Bayesian filter and smoother based on the variational Bayesian inference are proposed to approximately estimate the system state and the unknown noise parameters. Furthermore, the complexity analysis together with the controllability and observability for stochastic uncertain systems with multivariate skew t noises is given. Finally,the simulation results of the target tracking scenario verify the validity of the proposed algorithms.

关键词： Estimation methods Non-Gaussian noise Target tracking Uncertain systems Variational principles

Prospect and Reality of Concentration Gradient Cathode of Lithium-ion Batteries

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Chinese Journal of Structural Chemistry 2020年第1期39卷 11-15,1页

作者： LIU Tong-Chao PAN Feng AMINE Khalil Chemical Sciences and Engineering Division Argonne National LaboratoryArgonneIL 60439USA School of Advanced Materials Peking UniversityShenzhen Graduate SchoolShenzhen 518055China Material Science and Engineering Stanford UniversityStanfordCA 94305USA

Li[NixMnyCoz]O2 cathodes are currently the most practicable materials in the timing of developing high-performance rechargeable batteries for next-generation technologies.With the ever-growing demand for energy density,a significant breakthrough has been achieved by the controllable concentration design forming core-shell and concentration gradient structures to push Li[NixCoyMnz]O2 toward higher energy density,longer lifetime and safety.Herein,we review the recent progress on advanced concentration gradient cathode materials.Furthermore,we prospect that this novel approach will continuously extend its advantages in developing extremely fast charging and Co-free cathode materials in the near future.

关键词： lithium-ion batteries Li[NixMnyCoz]O2 core-shell structure concentration gradient structure

State estimate for stochastic systems with dual unknown interference inputs

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Chinese Journal of Aeronautics 2020年第9期33卷 2395-2407页

作者： Xiaoxue feng Shuhui LI feng pan School of Automation Beijing Institute of TechnologyBeijing 100081China Kunming-BIT Industry Technology Research Institute INC Kunming 650106China

Stochastic system state estimation subject to the unknown interference input widely exists in many fields,such as the control,communication,signal processing,and fault diagnosis.However,the research results are mostly limited to the stochastic system in which only the dynamic state model or the measurement model concerns the individual unknown interference input,and the state model and the measurement model are both with the same unknown interference input.State estimate of the stochastic systems where the state model and the measurement model contain dual Unknown Interference inputs(dual-UI)with different physical meanings and mathematical definitions is concerned here.Firstly,the decoupling condition with the Unknown Interference input in the State model(S-UI)is shown,which introduces the decoupled system with the adjacent Measurement concerned Unknown Interference inputs(M-UI)appearing in the state model and the measurement model.Then,through defining the Differential term of the adjacent M-UI(M-UID),the equivalent system with only M-UID in the state model is obtained.Finally,considering the design freedom of the equivalent system,the decoupling filter in the minimum mean square error sense and the adaptive minimum upper filter with different applicable conditions are represented to obtain the optimal and sub-optimal state estimate,respectively.Two simulation cases verify the effectiveness and superiority compared with the traditional methods.

关键词： Adaptive filter Decoupling filter State estimate Stochastic system Unknown interference input

A Bibliometrics Analysis on Academic Influence of Chinese Journal of Integrated Traditional and Western Medicine

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Chinese Journal of Integrative Medicine 2021年第2期27卷 148-152页

作者： LI Meng WENG pan-feng School of Marxism Xi'an Jiaotong UniversityXi'an(710049)China Health and Life Ethics Center Wenzhou Medical UniversityWenzhouZhejiang Province(325000)China

Objective:To illustrate the academic influence of Chinese Journal of Integrated Traditional and Western medicine,and provide suggestions for further development of the Journal.Methods:Taking the China National Knowledge Infrastructure(CNKI)database as main source and the Chinese Science Citation Database(CSCD)as reference,the researchers retrieved the related data of the Journal such as its publication quantity,citations,fund projects,authors,institutions and regions from 1981 to 2018,analyzed these data by means of bibliometrics and information visualization with EXCEL,SPSS,VISIO,MATLAB and other softwares.Results:Through the analysis of the main indicators,the relevant indicators of the Journal’s academic influence revealed the developing trend of the Journal.Cardiovascular and cerebrovascular diseases,endocrine,digestive system,pharmacological research of Chinese medicine and gynecology,as the hot topics in the discipline and academic,were clarified.Conclusions:All indicators show that the Journal is a high-quality journal reflecting the excellent achievements in the field of integrated Chinese and Western medicine in China.Through further analysis of relevant indicators,the authors put forward some specific suggestions on how to run the Journal well.

关键词： Chinese Journal of Integrated Traditional and Western Medicine academic influence impact factor highly cited author highly cited literature

Application of Nuclear Magnetic Resonance Spectroscopy in Metabolic Differences and Potential Biomarkers Screening in Rats with Polycystic Ovary Syndrome

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Chinese Journal of Biomedical Engineering(English Edition) 2022年第4期31卷 160-167页

作者： YU Jia pan Hai-feng WANG Han PAN Feng YANG Guang Jilin Province FAW General Hospital Changchun Jilin 130011China

Objective:To investigate the application of nuclear magnetic resonance(NMR)spectroscopy in the exploration of metabolic differences and potential biomarkers in rats with polycystic ovary syndrome(PCOS).Methods:PCOS model was established by subcutaneous injection of deoxy-epiandrosterone(DHEA)in 30 rats randomly selected from sixty 23-day-old SPF female SD rats and set as PCOS group,and the other 30 rats were subcutaneously injected with oil and set as oil group,PCOS model was successfully established by 20 days of injection in both groups,and blood samples were taken for biochemical detection and NMR detection analysis.At the same time,the body weight,ovarian weight and HE staining results of rats in both groups were observed.Results:Compared with the oil group,the rats in the PCOS group had higher body weight,ovarian weight and serum LH,FPG,T,E_(2)and HOMA levels,and lower serum FSH and INS levels(P<0.05).In the oil group,a large number of corpus luteum,follicles at different stages of development and multi-layered granulosa cells were observed under microscope after HE staining;In PCOS group,corpus luteum formation was only visible in some ovaries after HE staining,and all of them showed a higher number of cystic dilated follicles,thickened follicular membrane layer and less granulosa cell layer.The PCA score map of serum NMR profiles of the rats in the two groups showed that the samples were separated between the PCOS group and the oil group but the samples were aggregated within the group,and there were differences in blood metabolism between the PCOS model constructed by surface DHEA and the rats in the oil group.A total of 70 metabolites were detected in the serum samples of rats in the two groups by NMR technique,and 31 of them were different between the two groups,which can be classified into glucose,lipid,and and amino acid.There were significant differences in three metabolites,including isoleucine,valine,and creatine(P<0.01).Conclusion:There are differences in carbohydrate,lipid and amino acid metaboli

关键词： polycystic ovary syndrome nuclear magnetic resonance spectroscopy rats metabolic differences biomarkers

Modulated hydrocarbon distribution of gasoline deriving from butene conversion in the presence of syngas

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Journal of Energy Chemistry 2022年第10期31卷 416-421,I0010页

作者： Yi Ding feng Jiao Xiulian pan Xinhe Bao Department of Chemical Physics University of Science and Technology of ChinaHefei 230026AnhuiChina State Key Laboratory of Catalysis Dalian National Laboratory for Clean Energy2011-Collaborative Innovation Center of Chemistry for Energy MaterialsDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina University of Chinese Academy of Sciences Beijing 100049China

With the expansion of butene production capacity,clean and efficient conversion of mixed butene attracts increasing attention.Herein we report direct co-conversion of butene and syngas to highquality gasoline enabled by a bifunctional OXZEO catalyst comprising ZnCrO_(x) oxide and ZSM-5 zeolite.A gasoline selectivity of 71.6% at 98.1% butene conversion and 26.2% CO conversion have been obtained under the reaction conditions of 360℃,3 MPa and 3000 mL g^(-1) h^(-1).The space time yield of gasoline of0.25 g·g^(-1) h^(-1) is achieved.Interestingly,the presence of syngas can effectively facilitate iso-paraffin production while hindering the formation of aromatics.This is attributed to the prohibited hydrogen transfer aromatization process of butene on ZSM-5 in the presence of H2.Fu rthermore,the formation of isomers of gasoline range hydrocarbons is favored because the active intermediates generated from CO/H_(2) activation over ZnCrO_(x) oxide could react with butene over ZSM-5 zeolite.Thus,the product distribution among gasoline range hydrocarbons is modulated with reduced heavy aromatics and improved iso-paraffins,which is desirable for application as fuels.This provides an alternative environmentally friendly technology to utilize still increasing mixed butene.

关键词： Butene utilization Bifunctional catalysts OXZEO Syngas conversion Gasoline