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Preparation of high emissivity NiCr_2O_4 powders with a spinel structure by spray drying

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International Journal of Minerals,Metallurgy and Materials 2012年第2期19卷 173-178页

作者： Xu-dong Cheng Jie Min Zhen-qi Zhu wei-ping ye State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China School of Materials Science and Technology Wuhan University of Technology Wuhan 430070 China

Spray-drying was used to produce the high emissivity NiCr2O4 powders with a spinel structure. Preliminary investigations focused on fabricating the high emissivity powders for infrared radiation coatings and finding the relationship between microstructure and emissivity. The NiCr2O4 powders were characterized for composition, microstructure, and infrared emissivity by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, infrared radiant instrument, and Fourier transform infrared spectra （FT-IR）. Thermogravimetry and differential thermal analysis show that the appropriate baking temperature for NiCr2O4 powder preparation is about 1200？C. The emissivity measurement and FT-IR spectra show that, because of the special spinel structure, the NiCr2O4 powders have a high emissivity about 0.91. Spray-drying is a suitable method to produce the high emissivity ceramic powders.

关键词： emissivity infrared radiation spray drying powders ceramic materials nickel compounds chromium compounds

Synthesis of NiCr_2O_4 spinel coatings with high emissivity by plasma spraying

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International Journal of Minerals,Metallurgy and Materials 2012年第3期19卷 266-270页

作者： Zhen-qi Zhu Xu-dong Cheng wei-ping ye Jie Min School of Materials Science and Technology Wuhan University of Technology Wuhan 430070 China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China

Air plasma spraying （APS） was used to produce high emissivity coatings with a NiCr204 spinel structure. The relationship between the emissivity and the crystal structure was investigated. X-ray diffraction （XRD） analyses show that NiCr204 spinel has been fabri- cated with the space group Fd3m. Scanning electron microscope （SEM） photographs show that the coating consists of a laminated structure with homogeneous grains and high porosity because of the unique feature of plasma spraying. The emissivity measurement and Fourier transformation infrared radiation （FT-IR） spectra show that NiCr204 has a high emissivity of about 0.91 because of its special spinel structure APS is a suitable method to produce high emissivity coatings.

关键词： infrared radiation coatings plasma spraying emissivity crystal structure industrial ftLrnaces

Single stage dorsal inlay buccal mucosal graft with tubularized incised urethral plate technique for hypospadias reoperations

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Asian Journal of Andrology 2008年第4期10卷 682-686页

作者： wei-Jing ye ping ping Yi-Dong Liu Zheng Li Yi-Ran Huang Department of Urology Renji Hospital School of Medicine Shanghai Jiao Tong University Shanghai 200127 China

Aim： To report the experience with single stage dorsal inlay buccal mucosal grafts using the Snodgrass technique for complex redo cases. Methods： From May 2004 to December 2005, a total of 53 patients aged from 3 to 34 years old （average 11.62 ± 7.18 years） with failed previous hypospadias surgery were included in the present study. Indications included urethral strictures and repair breakdown. The unhealthy urethra was unroofed from the meatus in the ventral midline, a buccal mucosal graft was inlayed between the incised urethral plate and fixed to the corpora cavernosa. The neourethra was tubularized, and covered with subcutaneous （dartos） tissue and penile skin. Glanuloplasty was also performed in all cases. Outcome analysis included clinical follow-up, and endoscopy in 2 selected cases. Results： The buccal mucosal graft was 3.0-7.5 cm in length and 0.7-2.0 cm in width. All patients required glanuloplasty, with buccal mucosal grafts extended to the tip of the glans. After a follow-up of 14-30 months （mean 22.6 months）, the total complication rate was 15.1%, with five cases of fistula and three cases of stricture. Conclusion： Inlaying dorsal buccal mucosal grafts applying the Snodgrass technique is a reliable method for creating a substitute urethral plate for tubularization. The recurrent rate of urethral stricture and fistula is at an acceptable level for redo cases. This approach represents an effective, simple and safe option for reoperations.

关键词： hypospadias buccal mucosal graft urethroplasty

Study on Bicoordination Chiral Inducement Catalysis of (R)-4-Thiazolidinecarboxylic Acid

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Chinese Chemical Letters 2004年第12期15卷 1419-1422页

作者： Hui WANG wei wei PEI Guo Bin SUN wei ping ye College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 Coll. of Chem. and Molec. Eng. Peking University Beijing 100871 China

The bicoordination chiral inducement catalysis of (R)-4-thiazolidinecarboxylic acid inthe enantioselective borane reduction of prochiral ketones has been studied. The fact that theabsolute configuration of the main product can be changed by simply using different operationmethods was firstly verified. And the reason of bicoordination chiral inducement was discussed.

关键词： Bicoordination chiral inducement (R)-4-thiazolidinecarboxylic acid.

Optical Transient Source AT2021lfa:A Possible“Dirty Fireball”

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Research in Astronomy and Astrophysics 2024年第4期24卷 124-133页

作者： Xue-Mei ye Da-Ming wei Yi-Ming Zhu Zhi-ping Jin Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210023China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China National Astronomical Observatories/Nanjing Institute of Astronomical Optics&Technology Chinese Academy of SciencesNanjing 210042China CAS Key Laboratory of Astronomical Optics&Technology Nanjing Institute of Astronomical Optics&TechnologyNanjing 210042China

AT2021lfa,also known as ZTF21aayokph,was detected by the Zwicky Transient Facility on 2021 May 4,a 05:34:48 ***-up observations were conducted using a range of ground-based optical telescopes,as wel as Swift/XRT and VLA ***2021lfa is classified as an“orphan afterglow”candidate due to its rapid flux decline and its reddened color(g-r=0.17±0.14 mag).For an optical transient source without promp gamma-ray detection,one key point is to determine its burst *** we measure the burst time through fitting the initial bump feature of AT2021lfa and obtain its burst time as 2021 May 3,at 22:09:50 *** afterglowpy,we model the multi-band afterglow of AT2021lfa and find that the standard model canno reproduce the late radio observations *** that the microphysical parameters ε_(e),ε_(B)(the energy fraction given to electrons and magnetic field),andξN(the fraction of accelerated electrons)may vary with time we then model the afterglow of AT2021lfa taking into account the temporal evolution of the physical parameters ε_(e),ε^(B),and ξ_(N) and find in this case the multi-wavelength observations can be reproduced *** initial Lorentz factor of AT2021lfa can be estimated from the peak time of the early afterglow,which yields a value of about 18 suggesting that AT2021lfa should be classified as a“dirty fireball.”From the upper limit for the prompt emission energy of AT2021lfa,we obtain that the radiation efficiency is less than 0.02%,which is much smaller than that of ordinary gamma-ray bursts(GRBs).It is also interesting that the fitted values of jet angle and viewing angle are very large,θ_(c)~0.66 rad,θ_(v)~0.53 rad,which may lead to the low Lorentz factor and radiation *** compared with GRB afterglow samples,it is evident that the onset bump timescale of AT2021lfa satisfies the empirical relationships observed in GRB ***,the luminosity of AT2021lfa falls within the range of observations for GRB samples;howeve

关键词： gamma-rays:ISM methods:numerical radiation mechanisms:non-thermal

Privacy-Preserving Consensus-Based Distributed Economic Dispatch of Smart Grids via State Decomposition

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IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1250-1261页

作者： wei Chen Guo-ping Liu The authors are with the Center for Control Science and Technology Southern University of Science and TechnologyShenzhen 518055China

This paper studies the privacy-preserving distributed economic dispatch(DED)problem of smart *** autonomous consensus-based algorithm is developed via local data exchange with neighboring nodes,which covers both the islanded mode and the grid-connected mode of smart *** prevent power-sensitive information from being disclosed,a privacy-preserving mechanism is integrated into the proposed DED algorithm by randomly decomposing the state into two parts,where only partial data is *** objective is to develop a privacy-preserving DED algorithm to achieve optimal power dispatch with the lowest generation cost under physical constraints while preventing sensitive information from being *** this end,a comprehensive analysis framework is established to ensure that the proposed algorithm can converge to the optimal solution of the concerned optimization problem by means of the consensus theory and the eigenvalue perturbation *** particular,the proposed autonomous algorithm can achieve a smooth transition between the islanded mode and the grid-connected ***,rigorous analysis is given to show privacy-preserving performance against internal and external ***,case studies illustrate the feasibility and validity of the developed algorithm.

关键词： preserving autonomous mode

Soft coarse-grained particle model for particle-fluid systems

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Particuology 2024年第1期84卷 178-193页

作者： Yanhao ye Ji Xu wei Ge State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing100049China Innovation Academy for Green Manufacture Chinese Academy of SciencesBeijing100190China

By modeling a group of neighboring real particles as a single coarse-grained particle(CGP),discrete particle method(DPM)is now capable of simulating industrial-scale particle-fluid ***,a systematic approach to determine the CGP properties and develop their interaction models is still lacking,which casts uncertainty on the predictivity of the *** this study,collisions between predefined particle groups are analyzed to construct kernel functions for modeling the CGPs and then the model parameters are determined by equating the statistical properties of the CGPs and the real particles in the physical process *** approach is implemented for homogeneous cooling of granular gas,then demonstrated effective in simulating experimental fluidized beds.

关键词： Coarse-grain(CG) Discrete particle method(DPM) Fluidized bed Multi-scale simulation

The First Ground-based White Light Lunar Polarization Imaging:A New Kind of FeO Observation on the Near Side of the Moon

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Research in Astronomy and Astrophysics 2024年第6期24卷 1-6页

作者： wei-Nan Wang Jin-Song ping Ming-Yuan Wang Wen-Zhao Zhang Han-Lin ye Xing-wei Han Song-Feng Kou Changchun Observatory National Astronomical ObservatoriesChinese Academy of SciencesChangchun 130117China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 101408China Astronomy Department Beijing Normal UniversityBeijing 100875China International Center for Climate and Environment Sciences Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Nanjing Institute of Astronomical Optics and Technology Chinese Academy of SciencesNanjing 210042China

Lunar optical polarization is a fascinating phenomenon that occurs when sunlight reflects off the surface of the Moon and becomes *** study employs a novel split-focus plane polarimetric camera to conduct the initial white light polarimetric observations on the near side of the *** obtained the linear degree of polarization(DOP)parameters of white light by observation from the eastern and western hemispheres of the *** findings indicate that the white light polarization is lower in the lunar highland than in the lunar maria *** the analysis of lunar soil samples,we noticed and determined that the DOP parameters of white light demonstrate high consistency with iron oxide on the *** study may serve as a new diagnostic tool for the Moon.

关键词： techniques:photometric polarization methods:observational Moon

Dark Localized Waves in Shallow Waters:Analysis within an Extended Boussinesq System

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Chinese Physics Letters 2024年第4期41卷 32-37页

作者： Zhengping Yang wei-ping Zhong Milivoj Belic Department of Medical Science Shunde PolytechnicShunde 528300China Department of Electronic Engineering Shunde PolytechnicShunde 528300China Division of Arts and Sciences Texas A&M University at Qatar23874 DohaQatar

We study dark localized waves within a nonlinear system based on the Boussinesq approximation,describing the dynamics of shallow water *** symbolic calculus,we apply the Hirota bilinear method to transform an extended Boussinesq system into a bilinear form,and then use the multiple rogue wave method to obtain its dark rational *** the first-and second-order dark solutions,we examine the conditions under which these localized solutions exist and their spatiotemporal *** the selection of various parameters and by utilizing different visualization techniques(intensity distributions and contour plots),we explore the dynamical properties of dark solutions found:in particular,the first-and second-order dark rogue *** also explore the methods of their *** findings presented here not only deepen the understanding of physical phenomena described by the(1+1)-dimensional Boussinesq equation,but also expand avenues for further *** method can be extended to other nonlinear systems,to conceivably obtain higher-order dark rogue waves.

关键词： Boussinesq bilinear nonlinear