|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Effects of PyC shell thickness on the microstructure,ablation resistance of SiCnws/PyC-C/C-ZrC-SiC composites显示文摘SiC nanowires/pyrocarbon(SiCnws/PyC)core-shell structure toughenedC/C-ZrC-SiC composites were fabricated by CLVD process,and the influences of PyC shell thickness on the microstructure and ablation resistance of the composites were researched.The results presented that SiCnws/PyC core-shell structure had a linear shape,and the composites became dense with the increasing PyC thickness.When the thickness of PyC shell increased from 0 to 2.4μm,the density and thermal conductivity of the composites was improved gradually,but the coefficient of thermal expansion(CTE)decreased firstly and then increased.After the ablation test for 90 s,the ablation rates of the composites decreased continuously as the PyC thickness increased from 0 to 1.4μm,but increased when the PyC thickness was up to 2.4μm.Especially when the PyC thickness was 1.4μm,the linear and mass ablation rates of the composites were 71.25%and 63.01%lower than those of the composites without PyC shell.The reasons behind the remarkable improvement of anti-ablation property were that the proper PyC thickness could alleviate the CTE mismatch to promote the formation of complete oxide coating,improve the thermal conductivity to reduce heat corrosion and enhance the capability to limit the mechanical erosion. | Qinchuan He Hejun Li Xuemin Yin Jinhua Lu | 2021 | Journal of Materials Science & Technology2021，，12： | 4 |
| 2 | Grow defect-rich bamboo-like carbon nanotubes on carbon black for enhanced microwave absorption properties in X band显示文摘Due to the limited electromagnetic wave(EMW)loss capacity and agglomeration,carbon black(CB)gradually fails to meet the increasingly harsh demanding conditions.Herein,defect-rich bamboo-like carbon nanotubes(CNTs)were grown on CB by the process of chemical vapor deposition.CNTs prepared in situ on CB can assist it to build a developed multilevel conductive network and introduce plentiful CB/CNTs nano-interfaces.What’s more,the defects that accompany the growth of CNTs endow CNTs with a moderate conductivity and good impedance matching,thereby causing an effective microwave absorption(MA).Meanwhile,the high-density defects on CNTs can induce dipole polarization to further strengthen the EMW loss ability.The influence of CNTs with different growth time on MA performance has been explored.Profiting from the structural merits,the synthesized CB-CNT with CNTs growth time of 40 min exhibits the optimal absorbing property,which has the minimum reflection loss of-53.6 d B and maximum effective absorption bandwidth of 4.1 GHz with the thickness of 2.7 mm,covering almost the entire X band.The introduction of defect-rich CNTs significantly enhances the EMW loss ability of CB,which provides a rational strategy for the design of high-efficient microwave absorption materials. | Yameng Jiao Qiang Song Xuemin Yin Liyuan Han Wei Li Hejun Li | 2022 | Journal of Materials Science & Technology2022，，24： | 3 |
| 3 | Substrates and interlayer coupling effects on Mo1-xWxSe2 alloys显示文摘Two-dimensional(2D) transition metal dichalcogenides alloys are potential materials in the application of photodetectors over a wide spectral range due to their composition-dependent bandgaps. The study of bandgap engineering is important for the application of 2D materials in devices. Here, we grow the Mo1-xWxSe2 alloys on mica, sapphire and SiO2/Si substrates by chemical vapor deposition(CVD) method. Mo1-x Wx Se2 alloys are grown on the mica substrates by CVD method for the first time. Photoluminescence(PL) spectroscopy is used to investigate the effects of substrates and interlayer coupling force on the optical bandgaps of as-grown Mo1-xWxSe2 alloys. We find that the substrates used in this work have an ignorable effect on the optical bandgaps of as-grown Mo1-xWxSe2. The interlayer coupling effect on the optical bandgaps of as-grown Mo1-xWxSe2 is larger than the substrates effect. These findings provide a new way for the future study of the growth and physical properties of 2D alloy materials. | Fang Liang Hejun Xu Zuoyuan Dong Yafeng Xie Chen Luo Yin Xia Jian Zhang Jun Wang Xing Wu | 2019 | Journal of Semiconductors2019，40，6： | 2 |
| 4 | NiCoLDH nanosheets grown on MOF-derived Co_(3)O_(4) triangle nanosheet arrays for high-performance supercapacitor显示文摘Hierarchical Co_(3)O_(4)@NiCoLDH nanosheets(NSs)were prepared on carbon cloth through a multistep method,containing Metal-organic frameworks(MOF)-templated thermal annealing and electrodeposition.The triangle-shaped Co_(3)O_(4 NSs)were firstly obtained by thermal treatment of MOF templates in air.Then,ultrathin NiCoLDH_(NSs)were in-situ electrodeposited on the surface of Co_(3)O_(4NSs),constructing a core-shell structure.Benefiting the unique hierarchical structure,high conductivity of Co_(3)O_(4 NSs)core and large surface area of NiCoLDHNSs shell,the Co_(3)O_(4)@NiCoLDH_(NSs)array served as supercapacitor electrode exhibits excellent electrochemical properties,such as high specific capacitance of 1708 F g^(-1)(850 C g^(-1))at a current density of 1 A g^(-1),good rate capability,and excellent cycling stability.Further,the asymmetric supercapacitor assembled by Co_(3)O_(4)@NiCoLDH_(NSs)and activated carbon,also displays superior electrochemical perfo rmance with high energy density and power density.Remarkably,the strategy of constructing core-shell structure based on MOF templates could be extended to other electrochemical fields. | Xuemin Yin Hejun Li Ruimei Yuan Jinhua Lu | 2021 | Journal of Materials Science & Technology2021，，3： | 2 |
| 5 | Hierarchical,seamless,edge-rich nanocarbon hybrid foams for highly efficient electromagnetic-interference shielding显示文摘Lightweight,flexible,ultrahigh-performance electromagnetic-interfe rence(EMI)shielding materials are urgently required in the areas of aircraft/aerospace,portable and wearable electronics.Herein,1 D carbon nanotubes(CNT)and carbon nanofibers(CNF)with 2 D edge-rich graphene(ERG)are used to form a lightweight,flexible CNT-ERG-CNF hybrid foam.This foam was fabricated through a self-sacrificial templating chemical vapor deposition process,where nanocarbons bond through covalent bonding,forming a hierarchical 3 D hybridized carbon nanostructure.Multistage conductive networks and heterogeneous interfaces were constructed using edge-rich nanocarbons to increase the induced currents and interfacial polarization which makes great contributions to achieve high absorption electromagnetic shielding effectiveness(SEA).The CNT-ERG-CNF hybrid foam exhibits EMI shielding effectiveness(SE)exceeding55.4 dB in the X-band while the specific SE(SSE,SE divided by mass density)achieves 9200 dB cm^(3)g^(-1),which surpasses that of nearly all other carbon-based composite materials.Furthermore,the structural stability and durability of the flexible CNT-ERG-CNF hybrid foams is examined by measuring EMI SE after 10000 times cyclic bending.Remarkably,this work not only provides a new idea for preparing hierarchical carbon materials for a wide range of applications,but presents some fundamental insights for achieving higher absorption losses in EMI shielding materials. | Liyuan Han Qiang Song Kezhi Li Xuemin Yin Jiajia Sun Hejun Li Fengpei Zhang Xinran Ren Xi Wang | 2021 | Journal of Materials Science & Technology2021，，13： | 2 |
| 6 | Mapping QTLs on BTA6 affecting milk production traits in a Chinese Holstein population显示文摘A Chinese Holstein population with daughter design was analyzed using 14 microsatellites covering a map distance of 55.7 cM on chromosome 6 to fine map QTL for five milk production traits. 26 paternal half-sib families with 2356 daughters were involved. Two different approaches, linear regression approach and variance component ap-proach, were employed, with a one-QTL model and two-QTL model fitted. With a one-QTL model, the linear regression approach revealed a QTL near BMS470 with effects on milk yield, fat yield, protein yield, and fat percentage, and another QTL near BMS2460 for protein percentage. The variance component approach confirmed the results of linear regres-sion approach for the three yield traits, with the exception that the QTL for fat yield was mapped to a different position near BMS1242. The 95% confidence intervals resulted from linear regression, obtained by bootstrapping, were generally large, ranging from 31 to 53 cM, whereas the variance com-ponent approach revealed very small confidence intervals, calculated by LOD drop-off method, for the three yield traits, only 4―5 cM. With a two-QTL model, both approaches pro-vided strong evidence for the existence of two QTLs for the three yield traits. Along with the QTLs identified in one-QTL model analyses, the linear regression approach revealed a second QTL near BP7 with effects on all the three yield traits, whereas the variance component approach located the sec-ond QTL near ILSS035, BMS470, and BP7 for the three traits, respectively. | CHEN Huiyong ZHANG Qin WANG Chunkao SHU Juan MEI Gui YIN Cengceng HU Fang XU Jingjing GONG Weijia LI Hejun QIU Xiaotian | 2005 | Chinese Science Bulletin2005，50，16： | 1 |
| 7 | Templated synthesis of spinel cobaltite MCo_(2)O_(4) (M¼Ni, Co and Mn) hierarchical nanofibers for high performance supercapacitors显示文摘Rational construction of transitional metal oxides electrode materials with suitable structure and composition is an effective strategy of improving their electrochemical performance.Herein,novel MCo_(2)O_(4) hierarchical nanofibers(H-MCo_(2)O_(4)NFs,M¼Ni,Co and Mn)were fabricated by a multi-step selftemplating method using electrospun nanofibers as precursors.Benefiting from the unique structure,such as numerous of vertically interlinked nanosheets on the surface and 1D interwoven nanofibers networks,the obtained HeNiCo_(2)O_(4)NFs electrode exhibits a high specific capacitance of 1750 F g1(At a current density of 0.5 A g1),good rate capability(Capacitance retention of 70%at 20 A g1),and outstanding cycling stability(Capacitance retention of 92%after 6000 cycles).Moreover,the solid-state hybrid supercapacitor assembled by HeNiCo_(2)O_(4)NFs and activated carbon(AC),delivers a high energy density of 38.4 Wh kg1 at a power density of 800 W kg1,and excellent cycling stability.Thus,the HeNiCo_(2)O_(4)NFs is a promising candidate material for supercapacitors electrode and this self-templating method in this work also provides a new path for the preparation of one-dimensional hierarchical metallic oxides. | Xuemin Yin Hejun Li Ruimei Yuan Yameng Jiao Jinhua Lu | 2021 | Journal of Materiomics2021，7，4： | 1 |
| 8 | Metal-organic framework derived hierarchical NiCo_(2)O_(4) triangle nanosheet arrays@SiC nanowires network/carbon cloth for flexible hybrid supercapacitors显示文摘To overcome the disadvantages of traditional powder electrodes,such as the insufficient performance,the aggregation of active materials,and the complex fabrication process,rationally constructing free-standing electrode materials with hierarchical architecture is an effective and promising method,which could further improve the electrochemical properties.Herein,using metal-organic framework nanoarrays(MOFNAs)as self-sacrificial templates and SiC nanowires(SiCNWs)network as nanoscale conductive skeletons,we successfully fabricated the hierarchical core-shell SiCNWs@NiCo_(2)O_(4)NAs on carbon cloth(CC)substrate.Taking advantages of structural merits,such as hierarchical porous triangle-like NiCo_(2)O_(4)NAs,the interwoven SiCNWs network and conductive CC substrate,when evaluated as a binder-free supercapacitor electrode,the CC/SiCNWs@NiCo_(2)O_(4)NAs shows a high specific capacitance of 1604.7 F g^(-1)(specific capacity of 222.9 mA h g^(-1))at 0.5 A g^(-1),good rate performance,and excellent cycling stability.Significantly,the hybrid supercapacitor assembled with CC/SiCNWs@NiCo_(2)O_(4)NAs as the cathode and MOF derived CC/SiCNWs@CNAs as the anode,could deliver a high specific density of 49.9 W h kg^(-1) at a specific power of 800 W kg^(-1),stable cycling performance,and good flexibility.Impressively,this feasible strategy for fabricating hierarchical structure displays great potential in the field of energy storage. | Xuemin Yin Hejun Li Ruimei Yuan Jinhua Lu | 2021 | Journal of Materials Science & Technology2021，，22： | 1 |
| 9 | Construction of multi-structures based on Cu NWs-supported MOF-derived Co oxides for asymmetric pseudocapacitors显示文摘Cu@MOF core-shell nanowires are synthesized by introducing oxidizable and CTAB-modified metal nanowires as self-engaged templates and supporting MOFs for a one-dimension nanostructure.The following thermal process is controlled to obtain several one-dimension structure s ofCuCo-mixed materials,such as nanorods,single-shell and double-shell nanowires.The hollow structure for electrode materials enlarges the surface area,provides buffer space for electrolyte to accelerate the ion/charge transfers and for the structure to reduce injuries of volume expansion during cycling.Together with some other merits,such as adequate oxidation of the MOFs,small crystal grains of the material,and well-mixed Cu/Co oxides,the double-shell Cu@MOF nanowires(CuCo-DS5)applied for pseudocapacitors deliver advanced electrochemical performance with a specific capacitance of 563.8 F g^(-1)at 1 A g^(-1)as well as an outstanding cycling stability with a 92%retention after 3000 cycles at 5 A g^(-1).Meanwhile,an asymmetric pseudocapacitor constructed with the CuCo-DS5 and active carbon(AC)shows a high specific capacitance and energy density. | Ruimei Yuan Hejun Li Xuemin Yin Peipei Wang Jinhua Lu Leilei Zhang | 2021 | Journal of Materials Science & Technology2021，，6： | 1 |
| 10 | Optimization of the Swept Volume Ratio between the Compressor and the Active Displacer in an Efficient 20 K Thermal-Coupled Two-Stage Pulse Tube Cryocooler显示文摘As an important component of the stirling-type pulse tube cryocooler(SPTC),an efficient phase shifter can significantly improve the cooling capacity.Compared to the common phase shifter,the active warm displacer(AWD)has a wider phase adjustment range and therefore can obtain a better phase relationship easily.Based on a two-stage thermal-coupled SPTC operating in the 20 K range,this paper studied the influence of the swept volume ratio between the compressor and displacer.The research found that the swept volume ratio changes the cooling capacity and efficiency of the cryocooler mainly by changing the phase difference between the pressure wave and the volume flow at the cold end.It was found from the results of the simulation and experiments that there is an optimal displacement of the displacer(Xd)of 2.5 mm and an optimal phase angle of 15°to obtain the highest cooling efficiency while the displacement of the compressor is constant.The cooling capacity at 20 K is 1.3 W while the input electrical power of the second stage compressor is 202 W,which indicates an overall relative Carnot efficiency(rCOP)of 0.055 in terms of input electrical power.In addition,due to the reasonable setting of precooling temperature and capacity,the swept volume ratio and phase at the maximum cooling capacity and maximum efficiency are consistent in this study.The research improves the understanding of phase shifters and has guiding significance for the optimization of the SPTC working below 20 K. | YIN Wang LIU Shaoshuai SONG Jiantang WU Wenting HUI Hejun JIANG Zhenhua LI Nanxi ZHU Haifeng WU Yinong | 2023 | Journal of Thermal Science2023，32，6： | 0 |
| 11 | AN ULTRA-WIDEBAND ANTENNA FOR THE REINFORCED CONCRETE DETECTION显示文摘In this paper,an Ultra-Wideband(UWB) planar antenna is proposed for the reinforced concrete detection,which consists of a pair of planar waterdrop arms,a microstrip to coplanar parallel-strips transition and a shallow rectangular cavity.In order to overcome the disadvantages of the shallow cavity,some absorbing material is loaded to weaken the narrow-band effect of the cavity and the crosstalk interference.The simulated and measured results show that the proposed antenna has a large bandwidth from 0.48 GHz to 3.6 GHz with Voltage Standing Wave Ratio(VSWR) below 2 and a fractional bandwidth about 200% under the center frequency of 1.6 GHz,directional radiation characteristics and small late-time ringing in the time domain,which can be suitable for nondestructive detection of the reinforced concrete. | Shao Jinjin Xia Zhenghuan Ji Yicai Fang Guangyou Yin Hejun | 2013 | Journal of Electronics(China)2013，30，6： | 0 |
| 12 | CHAOTIC ELECTRON TRAJECTORIES IN A CIRCULAR FREE ELECTRON LASER显示文摘The motion of a relativistic electron is analyzed in the field configuration consisting of a circular wiggler magnetic field, an axial magnetic field, and the equilibrium self-electric and self-magnetic fields produced by the non-neutral electron ring. By generating Poincare surface-of-section maps, it is shown that when the equilibrium self-fields is strong enough, the electron motions become chaotic. Although the realistic circular wiggler magnetic field destroys the inte-grability of the electron motion as the equilibrium self-fields do, the role the latter plays to make the motions become chaotic is stronger than the former does. In addition, the axial magnetic field can restrain the occurrence of the chaoticity. | Yin Yuanzhao Yin Hejun(Institute of Electronics, Academia Sinica, Beijing 100080) | 1996 | Journal of Electronics(China)1996，13，2： | 0 |
| 13 | REFLECTION AND TRANSMISSION OF HARMONIC WAVES AT A PLANE INTERFACE BETWEEN LINEAR AND NONLINEAR DIELECTRICS显示文摘The laws of reflection and transmission of harmonic waves at a plane interface between a linear dielectric and a nonlinear dielectric are carefully analyzed. The exact expressions of the reflective and transmissive fields are derived. The further discussions are made to the fields at the conditions of vertical incidence and phase-matching. | Yin Hejun Lu Baowei Song Wenmiao Yin Yuanzhao(Institute of Electronics, Academia Sinica, Beijing 100080) | 1996 | Journal of Electronics(China)1996，13，1： | 0 |
| 14 | Two birds with one stone: Simultaneous fabrication of HfC nanowires and CNTs through efficient utilization of polymer-derived ceramics显示文摘Carbon nanotubes(CNTs) are fabricated in carbon cloth by ultilizing the waste gasses when fabricating hafnium carbide nanowires(HfC_(NWS)) through thermal pyrolysis of Hf-containing polymer precursor.The formed HfC_(NWS) are distributed uniformly on the surface of the carbon fibers in carbon/carbon(C/C) composites and display perfect single crystal appearance.The pyrolysis of the Hf-containing organic precursor provides hafnium and carbon source for the growth of HfC_(NWS).The released waste gasses containing CO,CH4and CO_(2)are the main carbon source for the growth of CNTs.Specifically,the flexural strength of HfC_(NWS) reinforced carbon/carbon(HfC_(NWS)-C/C) composites is enhanced by ~105% compared with pure C/C,and the CNTs/carbon cloth also displays improved electrochemical performance with respect to capacitor applications.The present study introduces a novel sustainable and eco-friendly process related to polymer-derived ceramics to form advanced ceramic nanocomposites and proposes a deep understanding of the growth mechanism of CNTs. | Yanqin Fu Yulei Zhang Xuemin Yin Liyuan Han Qiangang Fu Hejun Li Ralf Riedel | 2022 | Journal of Materials Science & Technology2022，，34： | 0 |
| 15 | Cu/Co mixed hierarchical tubular heterostructures for alkaline supercapacitors显示文摘The hierarchical hollow structures of electrode materials s of supercapacitors is effective for the large specific surface area and fast ions and charge transports.Cu nanowires as self-engaged templates provide sites and paths for the nucleation and growth of the ZIF-67.Meanwhile,Cu atoms can disperse into metal organic frameworks(MOFs)to form Cu-Co mixed oxides and construct heterostructures.In this case,Cu nanowires are used as a template and an activated part to improve the internal electronic structures.The electrochemical performance can be improved due to these features.Herein,Cu nanowires and MOFs are combined via a mild and efficient approach to fabricate Cu-Co-O/CuO electrode materials.This electrode exhibits excellent electrochemical performance with a specific capacitance of 834.1 F g^(-1) at 1 A g^(-1).The assembled asymmetric supercapacitor(ASC)shows an ultra-high energy density of 40.7 W h kg^(-1) at a power density of 915 W kg^(-1) and a good capacitance retention after 8000 cycles in a 2 M KOH aqueous solution.The results otained in this work indicate a strategy of the combination of reactive metals with metal organic frameworks used as electrode materials for electrochemical supercapacitors. | Ruimei Yuan Hejun Li Xuemin Yin Peipei Wang Jinhua Lu Leilei Zhang | 2021 | Journal of Materiomics2021，7，3： | 0 |
| 16 | Ore genesis of Badi copper deposit, northwest Yunnan Province, China: evidence from geology, fluid inclusions, and sulfur, hydrogen and oxygen isotopes显示文摘The Badi copper deposit is located in Shangjiang town, Shangri-La County, Yunnan Province. Tectonically,it belongs to the Sanjiang Block. Vapor–liquid two-phase fluid inclusions, CO_2-bearing fluid inclusions, and daughter-bearing inclusions were identified in sulfide-rich quartz veins. Microthermometric and Raman spectroscopy studies revealed their types of ore-forming fluids:(1) low-temperature, low-salinity fluid;(2) medium-temperature, low salinity CO_2-bearing; and(3) high-temperature, Fe-rich,high sulfur fugacity. The δ^(18)O values of chalcopyritebearing quartz ranged from 4.96‰ to 5.86‰, with an average of 5.40‰. The δD values of ore-forming fluid in equilibrium with the sulfide-bearing quartz were from-87‰ to-107‰, with an average of-97.86‰. These isotopic features indicate that the ore-forming fluid is a mixing fluid between magmatic fluid and meteoric water.The δ^(34)S values of chalcopyrite ranged from 13.3‰ to15.5‰, with an average of 14.3‰. Sulfur isotope values suggest that the sulfur in the deposit most likely derived from seawater. Various fluid inclusions coexisted in the samples; similar homogenization temperature to different phases suggests that the Badi fluid inclusions might have been captured under a boiling system. Fluid boiling caused by fault activity could be the main reason for the mineral precipitation in the Badi deposit. | Hejun Yin Jianguo Huang Tao Ren | 2018 | Acta Geochimica2018，37，4： | 0 |
| 17 | Flexible double-wall carbon foam/Cu-Co oxides based symmetric supercapacitor with ultrahigh energy density显示文摘Electrochemical supercapacitors are regarded as a promising electrochemical energy storage device,because of its fast chargeability,long cycle life,and high power density.The connection of porous carbon and extensive electroactive substances have significantly improved their performance.However,the unsuitable constructing strategy and unclear electrochemical mechanism lead to a mismatch between the fast double-layer effect and the sluggish Faradaic behavior at the electrode,degrading the energy density and capacitance performances.Herein,the construction strategy based on the double-wall carbon foam,carbon nanotubes and copper nanocubes provides enhanced electronic structure and ion transport path,resulting in accelerated proton transport and redox insertion/deinsertion processes,as well as surprising electrochemical behaviors of Cu-Co oxide on both positive and negative electrodes(927.9 and 427.0 F g^(−1)at 1 A g^(−1)).A flexible symmetric supercapacitor assembled with the SCF/CNT@Cu/Cu-Co-O delivers a extremely excellent performance.At 1 A g^(−1),the specific capacitance is 337.8 F g^(−1),the energy density hits 60 Wh kg^(−1)at the power density of 17.8 kW kg^(−1).At 10 A g^(−1),the energy density is up to 120.1 Wh kg^(−1),representing the top energy density of supercapacitors.Combining systematical structural optimization and mechanism study,this work broadens the fabricating strategy of hierarchical nanostructures and high-performance electrode materials for energy storage. | Ruimei Yuan Xuemin Yin Shengyue Gu Jingjing Chang Hejun Li | 2023 | Journal of Materials Science & Technology2023，，29： | 0 |
| 18 | Stable controlled growth of 3D CuO/Cu nanoflowers by surfactant-free method for non-enzymatic hydrogen peroxide detection显示文摘Sensitive, convenient and rapid detection of hydrogen peroxide(H_2 O_2) is highly desirable in fields like fundamental biological research, food industries, and clinical & environmental analysis. Herein, a hierarchical porous CuO/Cu flower-like active electrode material for non-enzymatic H_2 O_2 sensor was synthesized via a low-cost and one-step chemical oxidation of Cu powder in water bath without surfactants. In order to discuss the growth mechanism of the product, products with different growth time length were fabricated. The electro-catalysis of all products were first exhibited by cyclic-voltammetry,and the product under 6 h reaction shows the best result. The detailed electro-catalytic behaviors of the best product(under 6 h reaction) are characterized by cyclic-voltammetry and amperometry under alkaline conditions. The materials have high sensitivity of 103 μA mM^(-1) cm^(-2)(R^2= 0.9979), low detection limit of 2 μmol/L and wide concentration range(from 2 μmol/L to 19.4 mmol/L). Large specific surface area and stabled nanostructure enabled good features, such as stability and sensitivity for the H_2 O_2 determination. | Ruimei Yuan Hejun Li Xuemin Yin Leilei Zhang Jinhua Lu | 2018 | Journal of Materials Science & Technology2018，34，9： | 0 |
| 19 | 4-ELEMENT PLANAR ARRAY ANTENNA FOR UWB APPLICATION显示文摘A novel low-cost 4-element planar array antenna directly fed by a coaxial cable for Ultra-WideBand(UWB) application is presented. The proposed antenna consists of 2×2 bowtie elements and a simple 1:4 power divider feeding network. Compared to the basic bowtie element, the impedance bandwidth of the array antenna has a significant improvement that the low cut-off frequency is extended from 6 GHz of the bowtie element to 2 GHz. The measured results show that the proposed antenna has a large bandwidth of 2 GHz to 11 GHz for Voltage Standing Wave Ratio(VSWR)<2, and exhibits a bidirectional radiation pattern and a modest gain across the operating band and a peak gain of about 9 dBi at 11 GHz. | Chen Chao Shao Jinjin Meng Shengwei Fang Guangyou Yin Hejun | 2014 | Journal of Electronics(China)2014，31，3： | 0 |
| 20 | PULSE SHRINKING TIME-TO-DIGITAL CONVERTER FOR UWB APPLICATION显示文摘A kind of architecture of Time-to-Digital Converter(TDC) for Ultra-WideBand(UWB) application is presented. The proposed TDC is based on pulse shrinking, and implemented in a Field Programmable Gate Array(FPGA) device. The pulse shrinking is realized in a loop containing two Programmable Delay Lines(PDLs) or a two-channel PDL. One line(channel) delays the rising edge and the other line(channel) delays the falling edge of a circulating pulse. Delay resolution of PDL is converted into a digital output code under known conditions of pulse width. This delay resolution measurement mechanism is different from the conventional time interval measurement mechanism based on pulse shrinking of conversion of unknown pulse width into a digital output code. This mechanism automatically avoids the influence of unwanted pulse shrinking by any circuit element apart from the lines. The achieved relative errors for four PDLs are within 0.80%–1.60%. | Chen Chao Meng Shengwei Xia Zhenghuan Fang Guangyou Yin Hejun | 2014 | Journal of Electronics(China)2014，31，3： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员