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Finite Group Action and Gromov-Witten Invariants in Symplectic Four-Manifolds

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Acta Mathematica Sinica,English Series 2010年第12期26卷 2325-2334页

作者： Yong Seung cho department of Mathematics Ewha Womans University

Let a finite group act semi-freely on a closed symplectic four-manifold with a 2-dimensional fixed point set. Then we show that the relative Gromov-Witten invariants are the same as the invariants on the quotient set-... 详细信息

关键词： Finite group action Gromov-Witten invariant symplectic four-manifold

SUBSTRATE EFFECT ON hYdROGENATEd MICROCRYSTALLINE SILICON FILMS dEPOSITEd WITh VhF-PECVd TEChNIQUE

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Acta Metallurgica Sinica(English Letters) 2006年第4期19卷 295-300页

作者： h.d. Yang department of Electronic Engineering Jinan University Guangzhou 510632 China

Raman spectra and scanning electron microscope （SEM） techniques were used to determine the structural properties of microcrb＇stalline silicon （μc-Si：h） films deposited on different substrates with the very high frequency plasma-enhanced chemical vapor deposition （VhF-PECVd） technique. Using the Raman spectra, the values of crystalline volume fraction Xc and average grain size d are 86%, 12.3nm; 65%, 5.45nm; and 38%, 4.05nm, for single crystalline silicon wafer, coming 7059 glass, and general optical glass substrates, respectively. The SEM images further demonstrate the substrate effect on the film surface roughness. For the single crystalline silicon wafer and Coming 7059 glass, the surfaces of the μc-Si：h films are fairly smooth because of the homogenous growth or h＇ttle lattice mismatch. But for general optical glass, the surface of the μ-Si： h film is very rough, thus the growing surface roughness affects the crystallization process and determines the average grain size of the deposited material. Moreover, with the measurements of thickness, photo and dark conductivity, photosensitivity and activation energy, the substrate effect on the deposition rate, optical and electrical properties of the μc-Si：h thin films have also been investigated. On the basis of the above results, it can be concluded that the substrates affect the initial growing layers acting as a seed for the formation of a crystalline-like material and then the deposition rates, optical and electrical properties are also strongly influenced, hence, deposition parameter optimization is the key method that can be used to obtain a good initial growing layer, to realize the deposition of μc-Si：h films with device-grade quality on cheap substrates such as general glass.

关键词： hydrogenated microcrystalline silicon film VhF-PECVd (very high frequency plasma-enhanced chemical vapor deposition) substrate effect

SANdWICh-TYPE ThEOREMS FOR MEROMORPhIC MULTIVALENT FUNCTIONS ASSOCIATEd WITh ThE LIU-SRIVASTAVA OPERATOR

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Acta Mathematica Scientia 2012年第3期32卷 929-941页

作者： Nak Eun cho department of Applied Mathematics Pukyong National UniversityBusan 608-737Korea

The purpose of this article is to obtain some subordination and superordi- nation preserving properties of meromorphic multivalent functions in the punctured open unit disk associated with the Liu-Srivastava operator.... 详细信息

关键词： Subordination superordination meromorphic multivalent function Liu- Srivastava operator sandwich-type result

Study on adhesively-bonded surface of tapered double cantilever specimen made of aluminum foam affected with shear force

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Journal of Central South University 2015年第12期22卷 4521-4527页

作者：孙洪鹏 cho Jae-ung division of Mechanical Engineering Graduate School Kongju National University division of Mechanical and Automotive Engineering Kongju National University

Aluminum foam is widely used in diverse areas to minimize the weight and maximize the absorption of shock energy in lightweight structures and various *** presents a number of advantages,such as low density,incombustibility,non-rigidity,excellent energy absorptivity,sound absorptivity and low heat *** aluminum foam with an air cell structure was placed under the TdCB Mode II tensile load by using Landmark equipment manufactured by MTS to examine the shear failure *** angle of the tapered adhesively-bonded surfaces of specimens was designated as a variable,and three models were developed with the inclined angles differing from one another at 6°,8° and 10°.The specimens with the inclined angles of 6°,8° and 10° have the maximum reaction forces of 168 N,194 N when the forced displacements are 6,5 and 4.2 mm *** are three specimens with the inclined angles of 10°,8° and 6° in the order of maximum reaction *** the analysis result,the maximum equivalent stresses of 0.813 MPa and 0.895 MPa happened when the forced displacements of 6 mm and 5 mm proceeded at the models of 6° and 8°,respectively.A simulation was carried out on the basis of finite element method and the experimental *** results of the experiment and the simulation analysis are shown not different from each other ***,only a simulation could be confirmed to be performed in substitution of an experiment,which is costly and time-consuming in order to determine the shearing properties of materials made of aluminum foam with artificial data.

关键词： adhesive displacement force reaction shearing fracture characteristic tapered double cantilever beam(TdCB)

direct 4d printing of functionally graded hydrogel networks for biodegradable,untethered,and multimorphic soft robots

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International Journal of Extreme Manufacturing 2024年第2期6卷 407-416页

作者： Soo Young cho dong hae ho Sae Byeok Jo Jeong ho cho department of Chemical and Biomolecular Engineering Yonsei UniversitySeoul 03722Republic of Korea department of Mechanical Engineering Virginia TechBlacksburgVA 24061United States of America School of Chemical Engineering Sungkyunkwan UniversitySuwon 16419Republic of Korea SKKU Institute of Energy Science and Technology(SIEST) Sungkyunkwan UniversitySuwon 16419Republic of Korea

Recent advances in functionally graded additive manufacturing(FGAM)technology have enabled the seamless hybridization of multiple functionalities in a single *** robotics can become one of the largest beneficiaries of these advances,through the design of a facile four-dimensional(4d)FGAM process that can grant an intelligent stimuli-responsive mechanical functionality to the printed ***,we present a simple binder jetting approach for the 4d printing of functionally graded porous multi-materials(FGMM)by introducing rationally designed graded multiphase feeder *** graded cross-linking agents gradually form stable porous network structures within aqueous polymer particles,enabling programmable hygroscopic deformation without complex mechanical ***,a systematic bed design incorporating additional functional agents enables a multi-stimuli-responsive and untethered soft robot with stark stimulus *** biodegradability of the proposed 4d-printed soft robot further ensures the sustainability of our approach,with immediate degradation rates of 96.6%within 72 *** proposed 4d printing concept for FGMMs can create new opportunities for intelligent and sustainable additive manufacturing in soft robotics.

关键词： intelligent and sustainable additive manufacturing multi-material four-dimensional printing untethered soft robot multi-stimuli-responsive soft robot biodegradable soft robotics

Influence of potassium pyrophosphate in electrolyte on coated layer of AZ91 Mg alloy formed by plasma electrolytic oxidation

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中国有色金属学会会刊：英文版 2009年第4期19卷 824-828页

作者： Jin-Young cho duck-Young hWANG dong-h eon LEE Bongyoung YOO dong-hyuk ShIN department of Metallurgy and Materials Scienc e Hanyang University

The effect of potassium pyrophosphate in the electrolyte on plasma electrolytic oxidation(PEO) process for AZ91 Mg alloy was *** morphologies and chemical compositions of the coating layer on the AZ91 Mg alloy were evaluated and corrosion resistance was also estimated by potentiodynamic polarization *** coating layer on AZ91 Mg alloy coated from the Bath 2 containing 0.03 mol/L of potassium pyrophosphate for 360 s exhibited considerably dense structure and contained 11%-18%(mass fraction) of *** higher content of phosphorous of coating layer coated from Bath 2 could be detected at the bottom of oxide layer,which strongly implied that the phosphorous ion might be concentrated at the barrier *** potential of coating layer of AZ91 Mg alloy increased and corrosion current density decreased with increasing the concentration of potassium *** polarization resistance(Rp) of coating layer of AZ91 Mg alloy coated from Bath 2 was 4.65×107 Ω/cm2,which was higher than that(Rp=3.56×104 Ω/cm2) of the sample coated from electrolyte without potassium *** coating layer coated from Bath 2 containing 0.03 mol/L potassium pyrophosphate exhibited the best corrosion resistance.

关键词： AZ91镁合金合金涂层焦磷酸钾电解氧化等离子体电解质腐蚀电流密度耐腐蚀性

EFFECTS OF Pb COMPOUNd AddITIVES ON ThE PROPERTIES OF YBa_2Cu_3O_(7-δ)

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Acta Metallurgica Sinica(English Letters) 2005年第2期18卷 145-148页

作者： F.h.Li Z.G.Fan J.Wang C.S.Liu d.W.Soh Y.J.cho SchoolofMaterialandMetallurgy NortheasternUniversityShenyang110004China MyongjiUniversity Yongjin449-728SouthKorea

The melting temperature and critical transition temperature Tc of YBa2Cu3O7-δ with deferent content additives of PbO and BaPbO3 were studied. When PbO was doped in YBa2Cu3O7-δ, the melting temperature of YBa2Cu3O7-δ was reduced, however its superconductivity was weakened. From the XRd pattern of the sintered mixture of YBa2Cu3O7-δ and PbO, it was known that there was a reaction between YBa2Cu3O7-δ and PbO, and the product was BaPbO3. hence different contents of BaPbO3 (10mass%, 20mass% and 30mass%) were added in YBa2Cu3O7-δ. It was proved that there were no reactions between YBa2Cu3O7-δ and BaPbO3. And the superconductivity of the mixtures was much better than that of the samples with PbO additive.

关键词： YBa2Cu3O7-δ PbO additive melting temperature superconductivity

An efficient approach to characterizing and calculating carrier loss due to heating and barrier height variation in vertical-cavity surface-emitting lasers

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Chinese Physics B 2010年第1期19卷 361-365页

作者：吴坚 h.d.Summers School of Physics and Nuclear Energy Engineering Beijing University of Aeronautics and Astronautics School of Physics and Astronomy Cardiff University

It is important to determine quantitatively the internal carrier loss arising from heating and barrier height variation in a vertical-cavity surface-emitting quantum well laser （VCSEL）. however, it is generally difficult to realize this goal using purely theoretical formulas due to difficulty h, deriving the parameters relat^i~g to the quantum well structure. In this paper, we describe an efl：icient approach to characterizing and calculating the carrier loss due to the heating and the barrier height change in the VCSEL. In the method, the thermal carrier loss mechanism is combined with gain measurement and calculation. The carrier loss is re-characterized in a calculable form by constructing the threshold current and gain detuning-related loss current using the measured gain data and then substituting them for the quantum well-related parameters in the formula. The result can be expressed as a product of an exponential weight factor linked to the barrier height change and the difference between the threshold current and gain detuning-related loss current. The gain variation at cavity frequency due to thermal carrier loss and gain detuning processes is measured by using an AllnGaAs-AIGaAs VCSEL structure. This work provides a useful approach to analysing threshold and loss properties of the VCSEL, particularly, gain offset design for high temperature operation of VCSELs.

关键词： semiconductor laser vertical cavity surface emitting laser quantum well thermal carrier loss

The recent advances in scaffolds for integrated periodontal regeneration

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Bioactive Materials 2021年第10期6卷 3328-3342页

作者： hyun Nyun Woo Young Joon cho Solaiman Tarafder Chang h.Lee Center for dental and Craniofacial Research Columbia University Medical Center630 W.168 St.VC12-212New YorkNY10032USA

The periodontium is an integrated,functional unit of multiple tissues surrounding and supporting the tooth,including but not limited to cementum(CM),periodontal ligament(PdL)and alveolar bone(AB).Periodontal tissues can be destructed by chronic periodontal disease,which can lead to tooth *** support of the treatment for periodontally diseased tooth,various biomaterials have been applied starting as a contact inhibition membrane in the guided tissue regeneration(GTR)that is the current gold standard in dental ***,various biomaterials have been prepared in a form of tissue engineering scaffold to facilitate the regeneration of damaged periodontal *** a physical substrate to support healing of a single type of periodontal tissue to multi-phase/bioactive scaffold system to guide an integrated regeneration of periodontium,technologies for scaffold fabrication have emerged in last *** review covers the recent advancements in development of scaffolds designed for periodontal tissue regeneration and their efficacy tested in vitro and in *** and Cons of different biomaterials and design parameters implemented for periodontal tissue regeneration are also discussed,including future perspectives.

关键词： Periodontium Periodontitis Bioactive scaffold Multi-phase scaffold Periodontal regeneration