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| 1 | 基于Matlab的QPSK系统设计仿真显示文摘介绍了数字通信中的QPSK调制解调的原理,通过用Matlab编写脚本程序对QPSK通信系统的发射和接收过程的具体实现进行模拟仿真,绘出信号在理想信道和加噪信道中模拟传输时的时域图,并对各模块进行了频谱分析,所得到的结果与理论基本相符,对于理解QPSK系统的性能并在系统的实际应用上作进一步的设计,提供了有效的参考依据。 | 高博 杨燕 胡建军 | 2010 | 科学技术与工程2010，10，5： | 9 |
| 2 | Assessment of commutation failure in HVDC systems considering spatial-temporal discreteness of AC system faults显示文摘This paper presents a novel commutation failure(CF) assessment method considering the influences of voltage magnitude drop, phase shift, and spatial-temporal discreteness of AC system faults. The commutating voltage-time area is employed to analyze the spatial-temporal discreteness of AC system faults causing CF in high-voltage direct current systems, and the influences of fault position and fault time on CF are revealed. Based on this, a novel CF criterion is proposed, further considering the influence of voltage phase shift and the spatial-temporal discreteness. Then this research develops a new CF assessment method, which does not rely on electromagnetic transient simulations. A real case from the China Southern Power Grid is used to verify the practicability of the proposed method by comparing with simulation results obtained using PSCAD/EMTDC. | Huanhuan YANG Zexiang CAI Xiaohua LI Chaoyun YU | 2018 | Journal of Modern Power Systems and Clean Energy2018，6，5： | 5 |
| 3 | Dynamic and static performance optimization of dual active bridge DC-DC converters显示文摘High efficiency and fast dynamic response are two main control objectives for dual active bridge(DAB)DC-DC converters. Traditional extended phase shift(EPS)control can significantly enhance the conversion efficiency of DAB DC-DC converters by reducing current stress;however, it cannot fulfill fast dynamic response requirements. In this paper, a novel hybrid control scheme consisting of EPS control and direct power control(DPC),named as EPS-DPC, is proposed. EPS-DPC control has salient features in both efficiency and dynamic performance. In order to verify the outstanding performance of the proposed EPS-DPC scheme, an experimental comparison was carried out on a scale-down DAB DC-DC converter among several control strategies, including single phase shift control with traditional voltage-loop(SPS-TVL), EPS control with traditional voltage-loop(EPSVTL), and EPS-DPC. Experimental results have been high consistent with theoretical analysis, and verified these advantages of the proposed EPS-DPC scheme. | Nie HOU Wensheng SONG Yutong ZHU Xiao SUN Wei LI | 2018 | Journal of Modern Power Systems and Clean Energy2018，6，3： | 5 |
| 4 | HLS bunch current measurement system显示文摘Bunch current is an important parameter for studying the injection fill-pattern in the storage ring and the instability threshold of the bunch, and the bunch current monitor also is an indispensable tool for the top-up injection. A bunch current measurement (BCM) system has been developed to meet the needs of the upgrade project of Hefei Light Source (HLS). This paper presents the layout of the BCM system. The system based on a high-speed digital oscilloscope can be used to measure the bunch current and synchronous phase shift. To obtain the absolute value of bunch-by-bunch current, the calibration coefficient is measured and analyzed. Error analysis shows that the RMS of bunch current is less than 0.01 mA when bunch current is about 5 mA, which can meet project requirement. | YANG YongLiang MA TianJi SUN BaoGen LU Ping WANG JiGang ZOU JunYing TANG LeiLei | 2011 | Science China(Physics,Mechanics & Astronomy)2011，54，S2： | 3 |
| 5 | 一种基于时分的EBPSK多载波实现方式显示文摘为了实现扩展的二元相移键控(EBPSK)调制的多载波传输,提出了一种基于时分的EBPSK多载波实现方式.首先,利用叠加原理,通过观察冲击滤波器的输出波形,分析了多路EBPSK信号间干扰的原因;然后,给出了消除信号间干扰的具体思路,即将临道信号相对延迟,使各路载波的判决区域在时间上区分开,避免判决区域的碰撞;最后,通过仿真,对比了不同时间保护间隔下基于时分的EBPSK多载波与单载波的误码率性能.仿真结果表明,时间保护间隔为0时干扰较大,多载波的误码率性能较差.在合适的时间保护间隔下,多载波的误码率性能几乎与单载波一致.基于时分的EBPSK多载波实现方式能够有效消除各路EBPSK信号间的干扰,使得多路EBPSK信号同时传输且误码率性能损失不明显. | 张鹏 吴乐南 苗圃 | 2014 | 东南大学学报(自然科学版)2014，44，2： | 2 |
| 6 | Anomalous SmKS induced by postcritical reflection and refraction at the core-mantle boundary显示文摘Earth’s outer core is generally thought to be a well-mixed liquid consisting mostly of iron and a small amount of lighter elements.Recent seismic studies using Sm KS waves show that the top a few hundred kilometers of the outer core possess a P-wave velocity slightly lower than the PREM model,which cannot be explained by self-compression of a chemically homogeneous outer core.We investigated the Sm KS waveforms of a deep earthquake occurring beneath South America recorded by a large and dense seismic array in China,and measured the differential arrival times of the Sm KS pairs.We found significant waveform distortion of the Sm KS caused by postcritical refraction and reflection at the core-mantle boundary.This waveform distortion can introduce significant bias to the measured differential times,leading to incorrect estimate of P-wave velocity of the outer core.Whether stable stratification is occurring in outer core or not requires further seismic investigations. | Liwei Wang Fenglin Niu | 2019 | Science Bulletin2019，64，21： | 2 |
| 7 | Symplectic algebraic dynamics algorithm显示文摘Based on the algebraic dynamics solution of ordinary differential equations andintegration of ,the symplectic algebraic dynamics algorithm sn is designed,which preserves the local symplectic geometric structure of a Hamiltonian systemand possesses the same precision of the na ve algebraic dynamics algorithm n.Computer experiments for the 4th order algorithms are made for five test modelsand the numerical results are compared with the conventional symplectic geometric algorithm,indicating that sn has higher precision,the algorithm-inducedphase shift of the conventional symplectic geometric algorithm can be reduced,and the dynamical fidelity can be improved by one order of magnitude. | WANG ShunJin ZHANG Hua | 2007 | Science China(Physics,Mechanics & Astronomy)2007，50，2： | 2 |
| 8 | 100Gb/s WDM/OTN在电力系统中的应用研究显示文摘随着技术的发展,电力系统普遍应用的10 Gb/s波分复用系统(wavelength division multiplexing,WDM)/光传送网(optical tlansmission net,OTN)技术可能面临着更新换代,为探索100 Gb/s WDM/OTN在电力应用中存在的问题,分析100 Gb/s WDM/OTN技术的标准成熟情况、与40 Gb/s技术的比较、100 Gb/s技术的特点、在电力可能应用的场景、光纤、站距的选择,以及设备、保护方式、接口的选择及网络管理和维护等,指出100 Gb/s技术和标准已经成熟,电力系统应跳过40 Gb/s阶段直接采用100 Gb/s技术,电力系统现有光纤、站距基本可满足100 Gb/s应用要求,设备选择宜采用电交叉类型等。 | 王玉东 | 2016 | 智能电网2016，4，4： | 1 |
| 9 | PROPAGATION EFFECTS AND APPLICATION OF PHASE INFORMATION FOR C-BAND DUAL-POLARIZATION RADAR显示文摘As a study on exploiting and popularizing the advanced dual-polarization weather radartechnique in China,the physical mechanism for the propagation effect of the radar wave isdiscussed by using the widely adapted extended boundary condition method,and some theoreticresults are provided for improving rain measurement accuracy.Furthermore,phase information,another important characteristic quantity of microwave,is considered for tapping the potentialitiesof the new meteorological radar system. | 苏德斌 徐宝祥 | 1997 | Acta meteorologica Sinica1997，11，3： | 1 |
| 10 | An improved frequency shift method for ATI-SAR flat earth phase removal显示文摘An improved frequency shift method is proposed to remove the flat earth phase in ATI-SAR ocean surface motion detection in this study. First, two conventional flat earth effect removal methods(i.e., the frequency shift method and the orbital parameter method) are introduced and compared. Then, two improvements to frequency shift method are suggested. In the first improvement, the phase diagram is divided into several sub-blocks to calculate the phase fringe frequency. In the second improvement, a function between the phase of land regions and position is fitted to correct the residual flat earth phase based on the phase of the land regions that tend toward zero in an along-track interferogram. It is found that the improved frequency shift method is greatly improved;and it agrees well with the orbital parameter method, and achieves similar accuracy. | Yubin Zhang Jie Zhang Junmin Meng Chenqing Fan | 2019 | Acta Oceanologica Sinica2019，38，8： | 1 |
| 11 | Impacts of practical channel impairments on the downlink spectral efficiency of large-scale distributed antenna systems显示文摘Channel impairments are major limiting factors in the performance of large-scale antenna systems. In this paper, we analyze the impacts of practical channel impairments caused by pilot contamination,Doppler shift, and phase noise on the downlink spectral efficiency of large-scale distributed antenna systems(L-DASs) with maximum ratio transmission(MRT) and zero-forcing(ZF) beamforming, in which per user power normalization is considered. Using a joint channel model that allows study of the simultaneous impacts of these channel impairments, we derive accurate and tractable closed-form approximations for the ergodic achievable downlink rate, thereby enabling spectral efficiency analysis of L-DASs and an efficient evaluation of the impacts of the channel impairments. It is shown that channel impairments reduce the downlink spectral efficiency and have a significant impact on ZF beamforming. The asymptotic user rate limit is also determined, from which we analyze the asymptotic performance of L-DASs with channel impairments. The analytical results show that MRT and ZF beamforming achieve the same asymptotic performance limit even with channel impairments. It is also found that the use of a large-scale antenna array at the base station sides can weaken the impacts of channel impairments. | Jiamin LI Dongming WANG Pengcheng ZHU Xiaohu YOU | 2019 | Science China(Information Sciences)2019，62，2： | 1 |
| 12 | Linear Permanent-Magnet Pump and Stirrer for Molten Aluminium显示文摘A new type of contactless stirrer and/or pump has been developed for Aluminium industry.Large scale synchronously rotating permanent magnet cylinders,which are magnetized orthogonal to the axes,are used to create travelling magnetic field in Aluminium furnace through a thick bottom or wall,which induces stirring in a liquid metal pool similarly to traditional AC three-phase inductors.Flowrate of up to 600 tons per hour can be achieved with negligible energy dissipation even if the total wall thickness of the furnace is 30 cm.The advantage of the permanent magnet inductor is much lower energy consumption-maximum energy consumption of the stirrer to produce sufficiently high mechanical torque does not exceed 20 kW even for 600 ton per hour stirrer.Produced metal flow is quite similar to that,which is achieved by the AC three-phase induction stirrers offered by ABB and other companies.AC three-phase inductors exhibit very high Joule losses in the coils of the machine,but the permanent magnet system working at frequency in the range from0.5 Hz to 2 Hz produces negligible Joule losses both in liquid Aluminium as well as in stainless steel plate of the furnace bottom enclosure and in the permanent magnet material itself,so relatively weak air cooling is sufficient.The linear permanent magnet stirrer has been experimentally tested on a small scale lab model in a shallow pool of InGaSn eutectic.The tests confirm the predicted flow intensities and flow pattern,and give sufficient results for validation of the large scale flow simulations.Principal schematics of investigated system and the free surface deformation of the liquid metal due to action of the stirrer are shown below.The linear permanent magnet system may be used also as a contactless pump for liquid Aluminium in two-chamber furnaces,for tapping the liquid metal or for transportation and precision dozing.If high flow rate is required simultaneously with considerable elevation of the liquid metal level,the wall thickness of the channel should be lower and frequency of the travelling magnetic field higher comparing to the case of stirring application.Two sided pump has also been considered for a fiat channel,promising two times higher magnetic field induction and four times higher delivered pressure head.Seeing in perspective wide range applications of the proposed system a patent has been obtained. | Beinerts Toms Bojarevics Andris Gelfgat Yurii Bucenieks Imants | 2012 | Journal of Iron and Steel Research(International)2012，19，S1： | 0 |
| 13 | Progress of plasma density fluctuation measurements with phase contrast imaging on HL-2A tokamak显示文摘A CO2 laser-based phase contrast imaging(PCI) diagnostic has been developed on HL-2A tokamak.It can detect line integrated plasma density fluctuations by measuring the phase shift of laser beam after being scattered by the bulk plasma.The diagnosed radial region ranges from ρ≡r/a =0.625 to 0.7.32-channel HgCdTe detectors with alternative-current biased amplifiers are arranged in line at the imaging plane of the optical path.This PCI is able to diagnose density fluctuations with wavenumbers ranging from 2 to 15 cm-1 and the time resolution is better than 2 μs.The first experimental data were achieved in 2018 spring campaign of HL-2A tokamak.High performance is confirmed in different discharging configurations and makes it a keen tool in broadband turbulence investigations. | 龚少博 余羿 许敏 孙爱萍 兰涛 聂林 柯锐 龙婷 刘灏 吴一帆 袁博达 王华杰 袁金榜 石中兵 钟武律 毛世峰 叶民友 段旭如 | 2019 | Plasma Science and Technology2019，21，8： | 0 |
| 14 | Analysis of LCL-type resonant arc welding power supply and its steaty-state mathematical model显示文摘This paper presents the operation of LCL type resonant arc welding power supply with fixed frequency and its steady state mathematical model. Using MathCAD to get the results and compared it to the results of the SPICE simulative experiment, we verify this mathematical model is correct. | 任玉 蒋志宏 邓占锋 李洪文 张义 | 1999 | China Welding1999，8，2： | 0 |
| 15 | Measurement for Phase Difference Rate without Phase Ambiguity显示文摘Firstly,the direction finding solution at the midpoint of a single base array is given for the purpose of this paper and the several functions relation between phase and frequency is also described.Then,the expression of phase difference rate is described based on the multichannel phase difference measurement.With stripping time difference item correspond to the baseline length from phase difference rate,a function is extracted which signifies the differential characteristics of wavelength integer and phase difference in a unit of length.Simulation calculation found that the variation of differential function of path difference in a unit of length is very regular.The corresponding corrected value can is determine directly by distinguishing the range of differential item of phase difference obtained by actual measurement.Thus,the function expression can be obtained that is equivalence with the quondam differential function of path difference and that is nothing to do with the difference item of wavelength integer.On this basic,several parameters are analyzed by using the method of phase difference measurement without phase ambiguity.The research results in this paper may provide a powerful technical support for engineering practical design related to the phase measuring. | Yu Tao | 2019 | Journal of Electronic & Information Systems2019，1，1： | 0 |
| 16 | Deuteron Photodisintegration Between 250 and 750 MeV | Chen Hua-zhong Zhang Xi-zhen Han Wen-shu Chen Bao-qiu Jin Xing-nan (China Institute of Atomic Energy.P.O.Box 275(18),Beijing 102413) | 1995 | Chinese journal of nuclear physics1995，，1： | 0 |
| 17 | Single-shot phase-shifting digital holography with a photon-sieve-filtering telescope显示文摘A method of single-shot phase-shifting digital holography with a photon-sieve-filtering telescope is proposed.Three copy images with different phases are first generated by use of a monofocal photon-sieve filter in Kepler telescope,and then interfere with the reference plane wave by a beam combiner.The hologram is captured by a charge-coupled device(CCD)in one single exposure.The complex-valued amplitude of the test object can be reconstructed by three-step phase-shifting interferometry through three frames of extracted sub-interferograms from the single-exposure hologram.The principle and simulation experiments are carried out and verified the validity of our proposed method.This method can be applied for snapshot imaging and three-dimensional object construction. | 李优 李垚村 张军勇 张艳丽 李雪梅 | 2019 | Chinese Physics B2019，28，8： | 0 |
| 18 | Quark-antiquark scattering phase shift and meson spectral function in pion superfluid显示文摘We study the quark-antiquark scattering phase shift and meson spectral function in the pion superfluid described by the Nambu-Jona-Lasinio model. Meson mixing in the pion superfluid dramatically changes the full scattering phase shift and significantly broadens the spectral function of some collective modes. | 夏涛 胡进 毛施君 | 2019 | Chinese Physics C2019，43，5： | 0 |
| 19 | Simultaneous polarization separation and switching for 100-Gbps DP-QPSK signals in backbone networks显示文摘We propose a novel scheme of simultaneous polarization separation and switching, based on the orthogonallypolarized four-wave mixing(FWM) effect, for ultra-high-speed polarization multiplexing(Pol-MUX) fiber networks such as 100-Gbps and 400-Gbps backbone networks. We use theoretical and experimental analysis of the vector theory of FWM to successfully achieve polarization separation and all-optical switching by utilizing a 100-Gbps dual polarizationquadrature phase shift keying(DP-QPSK) signal and two orthogonally-polarized pumps. Both of the polarization-separated QPSK signals have clear constellation diagrams, with root mean square(RMS) error vector magnitudes(EVMs) of 14.32%and 14.11% respectively. The wavelengths of idlers can be created at 30 different wavelengths, which are consistent with International Telecommunication Union-Telecommunication(ITU-T) wavelengths, by flexibly changing the wavelength of the pump light. Moreover, the idlers that have distinct wavelengths have power distributed in a range from-10 dBm to-15 dBm, which can support error-free transmission. The power penaltyis 5 d B lower than that of back-to-back(BTB)signal for both the X-and Y-polarization components measured at a bit error ratio(BER) of 3.8×10^(-3). Our experimental results indicate that this scheme has promising applications in future backbone networks. | 苏玉龙 冯欢 胡辉 汪伟 段弢 王屹山 司金海 谢小平 杨合宁 黄新宁 | 2019 | Chinese Physics B2019，28，2： | 0 |
| 20 | Impact of Rayleigh backscattering on single/dual feeder fiber WDM-PON architectures based on array waveguide gratings显示文摘The performance of colorless wavelength- division multiplexing passive optical network (WDM- PON) systems suffers from transmission impairments due to Rayleigh backscattering (RB). A single feeder fiber colorless WDM-PON architecture was modeled, simulated and analyzed at 25 km distance that sustained the noise induced by RB. We analytically compared the performances between single feeder and dual feeder WDM-PON architectures based on array waveguide gratings (AWGs). For single feeder WDM-PON, the high extinction ratios in both return-to-zeros (RZ)-shaped differential phase shift keying (DPSK) downstream and intensity remodulated upstream data signals helped to increase the tolerance to the noise induced by RB. However, a cost effective colorless system in dual feeder WDM-PON architecture was achieved without any optical amplification and dispersion compensation, low power penalty. These results illustrate that single feeder fiber architecture was cost effective in terms of deployment having a power penalty, while dual feeder fiber had lower power penalty thereby with better performance. Simulation results show that downstream and upstream signals achieved error-free performance at 10-Gbps with negligible penalty and enhanced tolerance to the noise induced by RB over 25 km single mode fiber. | Muhammad Idrees AFRIDI Jie ZHANG Yousaf KHAN Jiawei HAN Aftab HUSSEIN Shahab AHMAD | 2013 | Frontiers of Optoelectronics2013，6，1： | 0 |
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