http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Yuansheng Jin,Xiang-Gen Xia IEEE 2013 IEEE TRANSACTIONS ON COMMUNICATIONS Vol.61 No.1
<P>In this paper, a new interference nulling based channel independent precoding for MIMO-OFDM systems of n<SUB>t</SUB> transmit and n<SUB>r</SUB> receive antennas with insufficient cyclic prefix (CP) is proposed. By employing the notion of interference nulling, we show that our proposed channel independent precoding scheme can eliminate the inter-block interference (IBI) caused by the insufficient CP with higher bandwidth efficiency than the conventional zero-padded or a sufficient CP added block transmission system when n<SUB>r</SUB> ≤ n<SUB>t</SUB>. It is also shown that when n<SUB>r</SUB> >; n<SUB>t</SUB>, the IBI can be eliminated without the need of any zero-padding or adding CP or precoding when the OFDM block length is not too small.</P>
Jin, Yuansheng,Li, Shenghua,Peng, Haitao ENGINEERING TRIBOLOGY RESEARCH INSTITUTE KYUNGPOOK 1999 INTERNATIONAL SYMPOSIUM ON HIGH PERFORMANCE OF TRI Vol.1999 No.-
The investigations on tribological and quality evaluations of coatings and thin films which have been done over recent years in National Tribology Laboratory, Tsinghua University, were summarized. The main contents of the present overview include tribological evaluations of thermally sprayed ceramic and metallic coatings, tribological behaviors and mechanisms of coatings designed for high temperature lubrication and mechanisms of coatings designed for figh temperature lubrication, and quality evaluation of ceramic coatings and thin films by ultrasonics and micro-indentation.
EXAMINATION OF CRACK DEFECT AND ELASTIC MODULUS IN COATING MATERIAL BY SAM
Jin, Yuansheng,Peng, Haitao,Chen, Darong Chen ENGINEERING TRIBOLOGY RESEARCH INSTITUTE KYUNGPOOK 2000 INTERNATIONAL SYMPOSIUM ON HIGH PERFORMANCE OF TRI Vol.2000 No.-
Scanning acoustic microscopy (SAM) is a nondestructive inspection method that can afford information about the surface and subsurface of materials. Especially, SAM images embody the propagation and alteration of mechanical waves in materials, so it becomes imaginable to formulate the correlation between defects and mechanical properties of materials. In the present work. a Model THSAM-7B reflection-type acoustic microscope with frequency of 20 to 150 MHz was used to measure the elastic moduli CoCrMoSi+AL₂O₃TiO₂ coating and observe subsurface crack propagation in the coating materials during wear process. The result illustrates that SAM has an unique function to measure some mechanical properties of coating materials, such as elastic modulus, by V(z) curve capability and to correlate the propagation of subsurface cracks in coating materials during wear process.
Shixin Jin,Binjie Xin,Yuansheng Zheng,Shuhua Liu 한국섬유공학회 2018 Fibers and polymers Vol.19 No.1
Electric field plays a key role in electrospinning process for nanofiber and nanofiber yarn producing. The electric field distribution of the yarn manufacturing system is simulated by using finite element method analysis. The effects of electric field distribution and intensity were studied to analyze the influence of the electric field on the electrospun nanofiber yarn surface morphology, mechanical, thermal and water absorption properties. The results show that the morphology anddiameters of nanofiber and yarn were obviously affected by the electric field with changing the needle distance and applied voltage, which further influence the mechanical performance of the yarn. The needle distance does not much affect the thermal property of the PSA electrospun yarn, whereas the yarn obtains better thermal resistance properties at voltage of 25 kV. The nanoyarn electrospun and assembled under higher applied voltage is proved to have a better wicking property in our research.
Deposition and evaluation of MoNx films deposited by magnetron sputtering
Yajun Ma,Shenghua Li,Yuansheng Jin,Guoshun Pan,Yucong Wang,Simon C. Tung 한국트라이볼로지학회 2002 한국트라이볼로지학회 학술대회 Vol.2002 No.10
Molybdenum Nitrided (MoNx) films were deposited by DC planar magnetron sputtering. Silicon wafers and real nitrided stainless steel piston rings are employed as substrates. 12 different combinations of nitrogen and argon partial pressure, from 1:7 to 7:1, were applied to deposit MoNx films. X-ray diffraction (XRD) was used to determine the phase structures of films. When nitrogen vs. argon partial pressure is 1:7, the film is mainly MO₂N phase. With increase of nitrogen partial pressure, MoN phase emerges, but MO₂N phase still exists. Composition analysis with atomic emission spectrometry (AES) also agreed with this. The films have very high nanohardness (max 2400Hv) and good adhesion to the substrates.
Yunge Yu,Yan Liu,Fuli Zhang,Shixin Jin,Yaqian Xiao,Binjie Xin,Yuansheng Zheng 한국섬유공학회 2020 Fibers and polymers Vol.21 No.5
Polyurethane is a thermoplastic elastomer with excellent physical and chemical properties, the hydrophilicity ofPU limits the wide application in the waterproof and breathable materials market. In this study, SiO2 nanoparticles werehydrophobically modified by fluorosilane to prepare the fluorosilane-modified silica (F-SiO2), then it was added into thesynthesized polyurethane to prepare waterproof and breathable film (F-SiO2/PU) by electrospinning. Compared withpolyurethane membranes, F-SiO2/PU composite membranes could form rough morphological surface through the blendingof F-SiO2. The experimental results showed that the water contact angle of the composite nanofiber membranes increase withthe addition of the amount of modified silica, and the water contact angle reached 135 o when the dosage of F-SiO2 was5 wt%. The composite nanofiber membranes could be endowed with excellent waterproof performance, hydrophobicity(50 kPa) and moisture permeability (10.4 kg/m2·h). Besides, the prepared membrane can remain the hydrophobic propertystability under the dynamic tensile of large-scale deformation.
Jinhao Xu,Fuli Zhang,Binjie Xin,Yuansheng Zheng,Chun Wang,Shixin Jin 한국섬유공학회 2020 Fibers and polymers Vol.21 No.7
In this study, a novel polyvinylbutyral (PVB) bonded polypropylene (PP) composite fibrous mat was fabricated viamelt-electrospinning. In order to enhance the structure stability and mechanical properties of pristine PP fibrous mat system,preparation and characterization of the composite fibrous material by mixing different percentages of PVB and PP wasdesigned. The PVB can form bonding point between the PP fibers, which can ease the slip phenomenon between strainedfibers. The structure, morphology, tensile and tearing stress were measured systematically. The resultants exhibited that thetensile stress and tearing strength of composite fibrous mats were increased from 30.13 to 43.73 kPa and from 0.07 to 0.5 N,respectively. Meanwhile, the straight jet length and whipping range of each electrospun jets were analyzed via the imagescaptured by a high-speed photography system during the spinning process. The experimental resultants depicted thatcomposite system can lead to longer straight jet length and smaller whipping range.