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Synergetic effect of polydopamine particles and in-situ fabricated gold nanoparticles on charge-dependent catalytic behaviors

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Particuology 2019年第3期17卷 63-70页

作者： Xia han Xiaolu Chen Mengfei yan Honglai Liu Key Laboratory for Advanced Materials and School of Chemistry & Molecular Engineering East China University of Science and Technology Shanghai 200237 China

The versatile catechol unit of polydopamine (PDA) endows this molecule with a broad ranging adhesive properties and *** prepared free-standing PDA particles by a simple self-polymerization and these particles served as both an effective reductant and scaffold for a hybrid *** raspberrylike nanocomposites featured a high density of AuNPs uniformly deposited on PDA particles (PDA@Au).This system was prepared in-situ with assistance from the active catechol and amine groups of the PDA *** quantify the effect of the PDA carriers,we studied the catalytic activity of the PDA and PDA@Au *** PDA particles showed a pronounced charge-dependent catalytic activity for reduction of cationic methylene blue,negatively-charged 4-nitrophenolate,and zwitterionic rhodamine B in the presence of borohydride,whereas PDA@AuNPs showed catalytic activity with a less pronounced charge-dependence of the catalytic efficiency of the *** PDA particles served as a redox mediator and adsorbent accelerator in degradation of the dyes owing to its unique chemical structure.

关键词： Poiydopamine Gold nanoparticle Hybrid catalyst Adsorbent Redox mediator

Formation and characterization of metallic iron grains in coal-based reduction of oolitic iron ore

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International Journal of Minerals,Metallurgy and Materials 2017年第2期24卷 123-129页

作者： Yong-sheng Sun Yue-xin han yan-feng Li yan-jun Li School of Resources and Civil Engineering Northeastern University Shenyang 110819 China

To reveal the formation and characteristics of metallic iron grains in coal-based reduction, oolitic iron ore was isothermally re- duced in various reduction times at various reduction temperatures. The microstructure and size of the metallic iron phase were investigated by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and a Bgrimm process mineralogy analyzer. In the results, the re- duced Fe separates from the ore and forms metallic iron protuberances, and then the subsequent reduced Fe diffuses to the protuberances and grows into metallic iron grains. Most of the metallic iron grains exist in the quasi-spherical shape and inlaid in the slag matrix. The cumula- tive frequency of metallic iron grain size is markedly influenced by both reduction time and temperature. With increasing reduction temperature and time, the grain size of metallic iron obviously increases. According to the classical grain growth equation, the growth kinetic parameters, i.e., time exponent, growth activation energy, and pre-exponential constant, are estimated to be 1.3759 ± 0.0374, 103.18 kJ·mol^-1, and 922.05, respec- tively. Using these calculated parameters, a growth model is established to describe the growth behavior of metallic iron grains.

关键词： iron ore reduction metallic iron grain size growth kinetics activation energy

A survey on blockchain-based integrity auditing for cloud data

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Digital Communications and Networks 2022年第5期8卷 591-603页

作者： Haoxiang han Shufan Fei Zheng yan Xiaokang Zhou The State Key Lab of ISN School of Cyber EngineeringXidian University266 Xinglong Section of Xifeng RoadXi'anShaanxi710126China The Faculty of Data Science Shiga UniversityHikone522-8522Japan The RIKEN Center for Advanced Intelligence Project RIKENTokyo103-0027Japan

With the rapid advancement of cloud computing,cloud storage services have developed *** issue that has attracted particular attention in such remote storage services is that cloud storage servers are not enough to reliably save and maintain data,which greatly affects users’confidence in purchasing and consuming cloud storage *** data integrity auditing techniques for cloud data storage are centralized,which faces huge security risks due to single-point-of-failure and vulnerabilities of central auditing *** technology offers a new approach to this *** researchers have endeavored to employ the blockchain for data integrity *** on the search of relevant papers,we found that existing literature lacks a thorough survey of blockchain-based integrity auditing for cloud *** this paper,we make an in-depth survey on cloud data integrity auditing based on ***,we cover essential basic knowledge of integrity auditing for cloud data and blockchain ***,we propose a series of requirements for evaluating existing Blockchain-based Data Integrity Auditing(BDIA)***,we provide a comprehensive review of existing BDIA schemes and evaluate them based on our proposed ***,according to our completed review and analysis,we explore some open issues and suggest research directions worthy of further efforts in the future.

关键词： Blockchain Cloud storage Integrity auditing decentralization

Peering into the Milky Way by FAST:Ⅲ.Magnetic fields in the Galactic halo and farther spiral arms revealed by the Faraday effect of faint pulsars

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Science China(Physics,Mechanics & Astronomy) 2022年第12期65卷 39-54页

作者： Jun Xu JinLin han PengFei Wang Yi yan National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China School of Astronomy University of Chinese Academy of SciencesBeijing 100049China

The Five-hundred-meter Aperture Spherical radio Telescope(FAST)is the most sensitive radio telescope for pulsar *** make polarimetric measurements of a large number of faint and distant pulsars using the *** present the new measurements of Faraday rotation for 134 faint pulsars in the Galactic *** improvements are also made for some basic pulsar parameters for 15 of *** analyse the newly determined rotation measures(RMs)for the Galactic magnetic fields by using these 134 halo pulsars,together with previously available RMs for pulsars and extragalactic radio sources and also the newly determined RMs for another 311 faint pulsars which are either newly discovered in the project of the Galactic Plane Pulsar Snapshot(GPPS)survey or previously known pulsars without *** RM tomographic analysis in the first Galactic quadrant gives roughly the same field strength of around 2μG for the large-scale toroidal halo magnetic *** scale height of the halo magnetic fields is found to be at least 2.7±0.3 *** RM differentiation of a large number of pulsars in the Galactic disk in the Galactic longitude range of 26°dence for the clockwise magnetic fields(viewed from the north Galactic pole)in two interarm regions inside the Scutum arm and between the Scutum and Sagittarius arm,and the clockwise fields in the Local-Perseus interarm region and field reversals in the Perseus arm and beyond.

关键词： magnetic fields interstellar medium pulsars

General explicit solutions of most economic sections and applications for trapezoidal and parabolic channels

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Journal of Hydrodynamics 2019年第5期31卷 1034-1042页

作者： yan-cheng han Said MEasa Xue-ping Gao School of Water Conservancy and Environment University of JinanJinan 250022China department of Civil Engineering Ryerson UniversityTorontoOntarioCanada State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China

A channel section that has minimum construction cost is known as the most economic *** a section has important implications for economic ***,the most economic section is a complex optimization model with nonlinear objective function and constraints that is difficult to use by ordinary engineers.A general simple formula for the most economic section has not been *** this paper,the general differential equation for the most economic section is derived using Lagrange multiplier optimization method.A simple method to solve the most economic section is proposed that converted the optimization model into a general equation for the most economic section of any *** solving this equation,the dimensions of the most economic section are directly *** illustrate,the direct formula for trapezoidal section is *** aid application in practice,a simple explicit iterative formula for trapezoidal sections is *** direct and explicit iterative formulas were *** proposed method is superior to the classical optimization method and as such represent a valuable tool for open channel *** illustrate the versatility of the presented method,a direct formula for the parabolic section was also derived.

关键词： Most economic section channel parabolic explicit hydraulic section

Graphene-induced enhanced anticorrosion performance of waterborne epoxy resin coating

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Frontiers of Materials Science 2020年第2期14卷 211-220页

作者： Huan-yan XU Dan LU Xu han School of Materials Science and Engineering Harbin University of Science and TechnologyHarbin 150040China

In this work,waterborne epoxy resin E44 and graphene were employed as the matrix and nanofiller,respectively,to construct composite coatings with enhanced anticorrosion *** pattern and TEM observation indicated that the obtained graphene had a stacked structure of few-layer graphitic sheets with numbers of *** observations revealed that no defects or microcracks existed on the surface of graphene/epoxy coatings and the internal micropores and microcracks were filled by *** spectra displayed that all the characteristic absorption peaks were attributed to the epoxy resin cured with *** Tafel polarization curves showed that,as the graphene addition amount increased,the corrosive potential increased and the corrosive current *** results proved that the addition of graphene into epoxy coatings could not only increase the impedance arc in Nyquist plots,but also increase the impedance modulus at low ***,the enhanced anticorrosion mechanism was proposed and discussed.

关键词： graphene waterborne epoxy anticorrosion electrochemical property

New Bulb Turbine with Counter-rotating Tandem-runner

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Chinese Journal of Mechanical Engineering 2012年第5期25卷 919-925页

作者： han Fengqin yanG Lijing yan Shijie KUBOAT Takashi College of Electric Power South China University of Technology Guangzhou 510640 China Guangdong Technical College of Water Resources and Electric Engineering Guangzhou 510635 China

With the increasing demand for the clean sustainable power, the turbine design urgently turns to increase the capability significantly toward higher head for generating larger power. Currently, there are many studies in the field of the bulb turbine with single-stage runner, though reports about counter-rotating tandem-runner are rare. However, the further high-head application with the single-stage runner is very difficult to achieve due to the limit of the specific speed. In this paper, a new bulb turbine with the tandem-runner is designed in order to substantially increase the applicable limit toward higher head with larger power. A half of the net head is absorbed by the frontal runner which can generate output power, while the remaining half is absorbed by the rear runner. To generate the Euler energy required for the rear runner, the frontal runner has the counter-rotation against the rear runner so that the counter-rotating tandem-runner can meet the purpose of double head and power under the same size as the conventional bulb turbine. Supply and demand of Euler energy between the two runners are thoroughly optimized through the detailed flow analysis, in order to secure the stable operation. As a result, the interference of Euler energies between the outflow from the frontal runner and the inflow to the rear runner is confirmed to be very small on the counter-rotating interface between the two runners. The prediction method of on-cam performance between the two adjustable runners is also developed numerically, which provides optimal flow between the two runners. This research provides a theoretical basis for the optimal design and operation of the counter-rotating tandem-runner bulb turbines.

关键词： bulb turbine tandem-runner counter-rotating Euler energy power increase

CCNO mutation as a cause of primary ciliary dyskinesia:A case report

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World Journal of Clinical Cases 2022年第25期10卷 9148-9155页

作者： Yun-yan Zhang yan Lou han yan Hao Tang department of Respiratory and Critical Care Medicine Changzheng HospitalNaval Military Medical UniversityShanghai 200003China department of Orthopedic Oncology Spine Tumor CenterChangzheng HospitalNaval Military Medical UniversityShanghai 200003China department of Nephrology 905th Hospital of PLA NavyNaval Military Medical UniversityShanghai 200050China

BACKGROUND Primary ciliary dyskinesia(PCD)is an uncommon and genetically diverse *** to reports,most patients had more than 50 visits before being diagnosed with PCD,and the age at diagnosis was mostly in preschool,with an average age of about(10.9±14.4)years *** is a pathogenic gene that regulates the cell cycle,and its mutation is linked to the uncommon human genetic disorder *** the prevalence of the CCNO mutation is regarded to be exceptionally low,new reports of this mutation have increased in comparison to prior *** patients with CCNO are rare,and the incidence rate is no more than 2%in whole PCD *** SUMMARY Here,we report a case of a young Chinese woman diagnosed with PCD,who was found to carry the CCNO gene by whole exon gene *** this case,a young non-smoking Chinese female exhibiting recurrent cough and sputum at *** computed tomography(CT)showed bronchiectasis with infection,and sinus CT showed chronic ***,the patient had no visceral transposition and no history of *** electron microscope,it was found that cilia were short and reduced in number,and no power arm of cilia was *** exon sequencing analysis of the genome of the patient showed that the patient carried CCNO pathogenic gene,exon c.303C>A nonsense mutation and c.248_252dup frameshift *** clinical symptoms and CT images were improved after two months of treatment with aerosol inhalation and oral *** The results showed that CCNO is an important cause of *** mutant genes that may contribute to genetically diverse disorders like PCD have been discovered as sequencing technology has ***,the increase of genetic information makes it easier to diagnose uncommon diseases in clinical practice.

关键词： Primary ciliary immobility disorder CCNO gene Whole exon gene sequencing Clinical profiles Review of literature Case report

BEM/FDM Conjugate Heat Transfer Analysis of a Two-dimensional Air-cooled Turbine Blade Boundary Layer

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Journal of Thermal Science 2008年第3期17卷 199-206页

作者： Wang Zhenfeng yan Peigang Guo Zhaoyuan han Wanjin School of Energy Science and Engineering Harbin Institute of Technology Harbin 150001 China

A coupled boundary element method （BEM） and finite difference method （FDM） are applied to solve conjugate heat transfer problem of a two-dimensional air-cooled turbine blade boundary layer. A loosely coupled strategy is adopted, in which each set of field equations is solved to provide boundary conditions for the other. The Navier-Stokes equations are solved by HIT-NS code. In this code, the FDM is adopted and is used to resolve the convective heat transfer in the fluid region. The BEM code is used to resolve the conduction heat transfer in the solid region. An iterated convergence criterion is the continuity of temperature and heat flux at the fluid-solid interface. The numerical results from the BEM adopted in this paper are in good agreement with the results of analytical solution and the results of commercial code, such as Fluent 6.2. The BEM avoids the complicated mesh needed in other computation method and saves the computation time. The results prove that the BEM adopted in this paper can give the same precision in numerical results with less boundary points. Comparing the conjugate results with the numerical results of an adiabatic wall flow solution, it reveals a significant difference in the distribution of metal temperatures. The results from conjugate heat transfer analysis are more accurate and they are closer to realistic thermal environment of turbines.

关键词： Conjugate heat transfer Boundary elements Finite difference Air-cooled gas turbine.