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carbon Energy 2024年第7期6卷 134-149页

作者： Md.Selim Arif Sher Shah Hyeonjung Jung Vinod k.Paidi kug-Seung Lee Jeong Woo Han Jong Hyeok Park Department of chemical and Biomolecular Engineering Yonsei UniversitySeoulRepublic of Korea Department of chemistry University of North BengalRaja RammohunpurDarjeelingWest BengalIndia Department of Materials Science and Engineering Research Institute of Advanced MaterialsSeoul National UniversitySeoulRepublic of Korea Pohang Accelerator Laboratory Beamline DivisionPohangRepublic of Korea European Synchrotron Radiation Facility France

Mo_(2)c is an excellent electrocatalyst for hydrogen evolution reaction(HER).However,Mo_(2)c is a poor electrocatalyst for oxygen evolution reaction(OER).Herein,two different elements,namely co and Fe,are incorporated in Mo_(2)c that,therefore,has a finely tuned electronic structure,which is not achievable by incorporation of any one of the ***,the resulting electrocatalyst co_(0.8)Fe_(0.2)-Mo_(2)c-80 displayed excellent OER catalytic performance,which is evidenced by a low overpotential of 214.0(and 246.5)mV to attain a current density of 10(and 50)mA cm^(-2),an ultralow Tafel slope of 38.4 mV dec^(-1),and longterm stability in alkaline *** data demonstrates that co_(0.8)Fe_(0.2)-Mo_(2)c-80 requires the lowest overpotential(1.00 V)for OER and co centers to be the active *** ultrahigh catalytic performance of the electrocatalyst is attributed to the excellent intrinsic catalytic activity due to high Brunauer-Emmett-Teller specific surface area,large electrochemically active surface area,small Tafel slope,and low chargetransfer resistance.

关键词： fine-tuning electronic structures heteronanostructures Mo_(2)c multimetal(co/Fe) oxygen evolution reaction

A new technique for fault diagnosis in transformer insulating oil based on infrared spectroscopy measurements

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High Voltage 2024年第2期9卷 319-335页

作者： Mohamed M.F.Darwish Mohamed H.A.Hassan Nagat M.k.Abdel-Gawad Matti Lehtonen Diaa-Eldin A.Mansour Department of Electrical Engineering Faculty of Engineering at ShoubraBenha UniversityCairoEgypt Department of Electrical Engineering and Automation School of Electrical EngineeringAalto UniversityEspooFinland Department of Electrical Power Engineering Egypt-Japan University of Science and Technology(E-JUST)New Borg El-Arab CityEgypt Department of Electrical Power and Machines Engineering Faculty of EngineeringTanta UniversityTantaEgypt

condition monitoring of the insulating system within power transformers has a massive importance according to the electrical *** gas analysis(DGA)is frequently used for this ***,DGA lacks the necessary level of accuracy to identify all equipment faults,particularly in their initial stages of ***,it does not have the capability for real-time monitoring and relies on manual sampling and laboratory testing,causing potential delays in fault ***,the interpretation of DGA data necessitates specialised expertise,which may pose difficulties for smaller entities that have limited access to ***,the contribution of this research is to use infrared spectroscopy measurements as a new effective technique substituting the DGA method for fault diagnosis in insulating *** inception faults that were considered in this study were the electrical fault(discharges of high energy)and the thermal fault(300°cc).Regarding that,two test cells were crafted especially for serving the simulation processes inside the laboratory for both types of inception ***,six samples of pure paraffinic mineral oil were taken to be degraded in the *** that,all of them besides another sample that were not subjected to any kind of faults were taken to be examined by Fourier transform infrared(FTIR)spectroscopy to obtain an overview of the oil's behaviour in each fault *** that,the FTIR analysis was initially verified utilising the DGA ***,for further affirmation,the dielectric dissipation factor(DDF)for all samples was *** the final analysis,the verification tests provide experimental evidence about the outperformance of this new optical technique in detecting the transformer's inception faults in addition to proving its potential for being a superior alternative to the well-known traditional diagnostic techniques.

关键词： fault diagnosis spectroscopy

Engineered polycaprolactone–magnesium hybrid biodegradable porous scaffold for bone tissue engineering

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Progress in Natural Science:Materials International 2014年第5期24卷 561-567页

作者： Hoi Man Wong Paul k.chu Frankie k.L.Leung kenneth M.c.cheung keith D.k.Luk kelvin W.k.Yeung Department of Orthopaedics and Traumatology The University of Hong Kong Shenzhen key Laboratory for Innovative Technology in Orthopaedic Trauma The University of Hong Kong Shenzhen Hospital Department of Physics and Materials Science City University of Hong Kong Peking University Shenzhen Institution

In this paper, we describe the fabrication of a new biodegradable porous scaffold composed of polycaprolactone(PcL) and magnesium(Mg)micro-particles. The compressive modulus of PcL porous scaffold was increased to at least 150% by incorporating 29% Mg particles with the porosity of 74% using Micro-cT analysis. Surprisingly, the compressive modulus of this scaffold was further increased to at least 236% when the silane-coupled Mg particles were added. In terms of cell viability, the scaffold modified with Mg particles significantly convinced the attachment and growth of osteoblasts as compared with the pure PcL scaffold. In addition, the hybrid scaffold was able to attract the formation of apatite layer over its surface after 7 days of immersion in normal culture medium, whereas it was not observed on the pure PcL scaffold. This in vitro result indicated the enhanced bioactivity of the modified scaffold. Moreover, enhanced bone forming ability was also observed in the rat model after 3 months of implantation. Though bony in-growth was found in all the implanted scaffolds. High volume of new bone formation could be found in the Mg/PcL hybrid scaffolds when compared to the pure PcL scaffold. Both pure PcL and Mg/PcL hybrid scaffolds were degraded after 3 months. However, no tissue inflammation was observed. In conclusion, these promising results suggested that the incorporation of Mg micro-particles into PcL porous scaffold could significantly enhance its mechanical and biological properties. This modified porous bio-scaffold may potentially apply in the surgical management of large bone defect fixation.

关键词： Magnesium Polycaprolactone Biodegradability Biocompatibility Mechanical properties

Motion and Special Relativity in complex Spaces

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Journal of Applied Mathematics and Physics 2024年第1期12卷 330-361页

作者： Jerzy k. Filus Department of Mathematics and computer Science Oakton College Des Plaines IL USA

A natural extension of the Lorentz transformation to its complex version was constructed together with a parallel extension of the Minkowski M4 model for special relativity (SR) to complex c4 space-time. As the [signed] absolute values of complex coordinates of the underlying motion’s characterization in c4 one obtains a Newtonian-like type of motion whereas as the real parts of the complex motion’s description and of the complex Lorentz transformation, all the SR theory as modeled by M4 real space-time can be recovered. This means all the SR theory is preserved in the real subspace M4 of the space-time c4 while becoming simpler and clearer in the new complex model’s framework. Since velocities in the complex model can be determined geometrically, with no primary use of time, time turns out to be definable within the equivalent theory of the reduced complex c4 model to the c3 “para-space” model. That procedure allows us to separate time from the (para)space and consider all the SR theory as a theory of c3 alone. On the other hand, the complex time defined within the c3 theory is interpreted and modeled by the single separate c1 complex plane. The possibility for application of the c3 model to quantum mechanics is suggested. As such, the model c3 seems to have unifying abilities for application to different physical theories.

关键词： Special Relativity complex Space and Time Models and Dramatic SR Simplification complex Time and Space Separation complex Time Interpretation

Special Relativity’s “Newtonization” in complex “Para-Space”: The Two Theories Equivalence Question

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Journal of Applied Mathematics and Physics 2024年第7期12卷 2421-2451页

作者： Jerzy k. Filus Department of Mathematics and computer Science Oakton College Des Plaines IL USA

complex model, say c3, of “para-space” as alternative to the real M4 Minkowski space-time for both relativistic and classical mechanics was shortly introduced as reference to our previous works on that subject. The actual aim, however, is an additional analysis of the physical and para-physical phenomena’ behavior as we formally transport observable mechanical phenomena [motion] to non-real interior of the complex domain. As it turns out, such procedure, when properly set, corresponds to transition from relativistic to more classic (or, possibly, just classic) kind of the motion. This procedure, we call the “Newtonization of relativistic physical quantities and phenomena”, first of all, includes the mechanical motion’s characteristics in the c3. The algebraic structure of vector spaces was imposed and analyzed on both: the set of all relativistic velocities and on the set of the corresponding to them “Galilean” velocities. The key point of the analysis is realization that, as a matter of fact, the relativistic theory and the classical are equivalent at least as for the kinematics. This conclusion follows the fact that the two defined structures of topological vector spaces i.e., the structure imposed on sets of all relativistic velocities and the structure on set of all “Galilean” velocities, are both diffeomorphic in their topological parts and are isomorphic as the vector spaces. As for the relativistic theory, the two approaches: the hyperbolic (“classical” SR) with its four-vector formalism and Euclidean, where SR is modeled by the complex para-space c3, were analyzed and compared.

关键词： Special Relativity’s Hyperbolic Versus circular Versions Galilean kinematics Partial Equivalence of SR and Newton’s Theories Algebra of Relativistic and the corresponding Galilean Velocities

Design and fabrication of automated sedimentation-based separation and siphon-based extraction for detection of allergic reaction on a centrifugal microfluidic disc

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chinese Optics Letters 2010年第10期8卷 957-959页

作者： Q. L. chen H. P. Ho k. L. cheung S. k. kong Y. k. Suen Y. W. kwan c. k. Wong center for Advanced Research in Photonics and Department of Electronic Engineering The Chinese University of Hong Kong Hong Kong China Department of Biochemistry The Chinese University of Hong Kong Hong Kong China School of Biomedical Sciences The Chinese University of Hong Kong Hong Kong China Department of chemical Pathology The Chinese University of Hong Kong Hong Kong China

We report the design and fabrication of a novel and fully integrated polymer-based centrifugal microfluidic disc for rapid automatic allergens detection. All essential steps for a single test including flow valving, sequencing, mixing, separation, extraction, and sedimentation for final detection are automatically conducted within 30 min on a centrifugal microfluidic disc. Our design features a siphon-based valving and analyte extraction structure where the released analyte is separated and subsequently extracted by a siphon valve into the detection chamber. Incorporating the siphon valve and a series of capillary valves, we realize automated detection of allergic reaction on a centrifugal microfluidic disc.

关键词： Adaptive optics Diffuse optical imaging Photolithography Polydimethylsiloxane Polymethyl methacrylate

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Development and Validation of an Instrument to Measure STEM Undergraduate Students’ comprehensive Educational Process

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Frontiers of Education in china 2019年第4期14卷 575-611页

作者： ZHUANG Tengteng cheung Alan c.k. LAU Wilfred W.F. TANG Yipeng Department of Educational Administration&Policy Faculty of EducationThe Chinese University of Hong KongHong KongChina Department of curriculum and Instruction Faculty of EducationThe Chinese University of Hong KongHong KongChina college of Education Capital Normal UniversityBeijing 100089China

This study reports the development and validation of an instrument,“Undergraduate STEM Educational Process Questionnaire”(USEPQ)to assess the learning experiences of STEM(science,technology,engineering and mathematics)-major undergraduates from the perspective of a conceptualized comprehensive STEM educational process framework that consists of key essentials such as course learning and instruction,educational environment,assessment methods,and unique STEM *** Factor Analysis and confirmatory Factor Analysis performed on independent samples indicate that the finalized 9-factor,41-item USEPQ possesses a stable factor structure and sound psychometric *** factors of the validated scale are classroom Instruction of courses,Support from Faculty Members,Alternative Assessment Methods,cooperative Learning,Resources and Service,Academic competition,cross-discipline Features of Program courses,connectedness of Program courses,and Examination Difficulty.

关键词： higher education educational process STEM program,measurement instrument development and validation

Enhancing visible-light-driven NO oxidation through molecular‐level insights of dye-loaded sea sands

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Rare Metals 2024年第2期43卷 543-554页

作者： Yu-Han Li Bang-Fu chen Sónia A.c.carabineiro You-Yu Duan Ping Tan Wing-kei Ho Fan Dong Engineering Research center for Waste Oil Recovery Technology and Equipment Ministry of EducationChongqing Key Laboratory of Catalysis and New Environmental MaterialsChongqing Technology and Business UniversityChongqing400067China Nanchang Institute of Technology Nanchang33044China LAQV-REQUIMTE Department of ChemistryNOVA School of Science and TechnologyUniversidade NOVA de Lisboa2829-516CaparicaPortugal college of Physics and center of Quantum Materials and Devices Chongqing UniversityChongqing401331China Department of Science and Environmental Studies The Education University of Hong KongHong Kong999077China

Natural minerals,abundant and easily obtained through simple physical processing,offer a cost-effective and environmentally friendly solution for dyeing wastewater disposal and air pollution *** study investigates the photocatalytic removal of NO using natural different types of dyes,loaded on natural sand,under visible light *** examining various coating concentrations of dyes and sand weights,we discovered that sand loaded with Rhodamine B(RhB)exhibits high activity for the photo-oxidation of NO.A combination results of X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),Fourier transform infrared spectroscopy(FTIR)and thermogravimetric(TG)analyses confirm the presence of SiO_(2),cacO_(3),Al_(2)O_(3)and iron oxides as the main components of the ***,studying RhB-loaded individual components reveals that cacO_(3)plays a crucial role in enhancing the NO removal *** results and theoretical calculations demonstrate the establishment of a directional charge transfer channel from cacO_(3)to RhB,facilitating the adsorption and activation of molecular NO and O_(2).This work not only promotes the utilization of natural mineral resources but also enriches the fields of environmental photochemistry and semiconductor photocatalysis.

关键词： Sand dyes Rhodamine B Photo-oxidation of NO Visible light illumination

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Hydrogenic Donor in a Spherical Quantum Dot with Different confinements

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chinese Physics Letters 2009年第8期26卷 309-312页

作者： A. John peter k. Navaneethakrishnan Govt. Arts college Melur-625 106 Madurad India Madurai kamaraj-University Madurai-625 021 India

Binding energies of a hydrogenic donor in a spherical GaAs quantum dot surrounded by Ga1-xA4xAs matrix are calculated. The results are presented for realistie barrier heights corresponding to different values of x （x 〈 0.4）. The calculations are performed under two different conditions：（i） a spherical dot with square well confinement and （ii） a dot with parabolic potential well confinement. The results show that （i） the donor ionization energies are always higher under parabolic confinement as compared to a dot of the same radius under square well confinement and （ii） the oscillator strengths coupling ground state with excited states are two orders larger under parabolic confinement. Our results are in agreement with the results of other researchers.

关键词： No English keyword

Influence of degree of interlock on confined strength of jointed hard rock masses

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Journal of Rock Mechanics and Geotechnical Engineering 2020年第6期12卷 1152-1170页

作者： Navid Bahrani peter k.kaiser a Department of civil and Resource Engineering Dalhousie UniversityHalifaxNova ScotiaCanada b Bharti School of Engineering Laurentian UniversitySudburyOntarioCanada

The strength of jointed rock mass is strongly controlled by the degree of interlock between its constituent rock *** degree of interlock constrains the kinematic freedom of individual rock blocks to rotate and slide along the block forming *** HoekeBrown(HB)failure criterion and the geological strength index(GSI)were developed based on experiences from mine slopes and tunneling projects in moderately to poorly interlocked jointed rock *** has since then been demonstrated that the approach to estimate the HB strength parameters based on the GSI strength scaling equations(called the‘GSI strength equations’)tends to underestimate the confined peak strength of highly interlocked jointed rock masses(***>65),where the rock mass is often non-persistently jointed,and the intact rock blocks are strong and *** estimation of the confined strength of such rock masses is relevant when designing mine pillars and abutments at great depths,where the confining pressure is high enough to prevent block rotation and free sliding on block *** this article,a grain-based distinct element modeling approach is used to simulate jointed rock masses of various degrees of interlock and to investigate the influences of block shape,joint persistence and joint surface condition on the confined peak *** focus is on non-persistently jointed and blocky(persistently jointed)rock masses,consisting of hard and homogeneous rock blocks devoid of any strength degrading defects such as *** results from this investigation confirm that the GSI strength equations underestimate the confined strength of highly interlocked and non-persistently jointed rock ***,the GSI strength equations are found to be valid to estimate the confined strength of persistently jointed rock masses with smooth and non-dilatant joint surfaces.

关键词： Rock mass strength Degree of interlock Non-persistently jointed rock mass Blocky rock mass Geological strength index(GSI) GSI strength equations

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