期刊文献+
共找到1,197篇文章
< 1 2 60 >
每页显示 20 50 100
Equalization for continuous phase modulation over frequency-selective fading channels 被引量:2
1
作者 JIN Xiao-dong ZHAO Min-jian +1 位作者 SUN Ling SHEN Wen-li 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2007年第12期1884-1888,共5页
This paper presents an equalization algorithm for continuous phase modulation (CPM) over frequency-selective channels. A specific training sequence is first embedded in each data packet. By recursive least-squares ... This paper presents an equalization algorithm for continuous phase modulation (CPM) over frequency-selective channels. A specific training sequence is first embedded in each data packet. By recursive least-squares (RLS) estimation, the channel information parameters can be acquired, and a fractionally Simulation results show that the proposed algorithm can acquire the spaced equalizer performs joint decoding and equalization. channel information parameters rapidly and accurately, and that the fractionally spaced equalizer can eliminate the intersymbol interference (ISI) effectively, and is not sensitive to timing inaccuracy, so this algorithm can be exploited for demodulation system in burst mode. 展开更多
关键词 M-ary continuous phase modulation (CPM) Channel-estimation Joint decoding and equalization Fractionally spaced
下载PDF
SERIALLY CONCATENATED CONTINUOUS PHASE MODULATION WITH REDUCED ITERATIVE DEMODULATION AND DETECTION 被引量:3
2
作者 Sun Jinhua Li Jiandong Jin Lijun 《Journal of Electronics(China)》 2007年第1期16-22,共7页
A reduced state Soft Input Soft Output (SISO) a posteriori probability algorithm for Seri-ally Concatenated Continuous Phase Modulation (SCCPM) is proposed in this paper. Based on the Reduced State Sequence Detection ... A reduced state Soft Input Soft Output (SISO) a posteriori probability algorithm for Seri-ally Concatenated Continuous Phase Modulation (SCCPM) is proposed in this paper. Based on the Reduced State Sequence Detection (RSSD),it has more general form compared with other reduced state SISO algorithms. The proposed algorithm can greatly reduce the state number,thus leads to the computation complexity reduction. It also minimizes the degradation in Euclidean distance with decision feedback in the reduced state trellis. Analysis and simulation results show that the perform-ance degradation is little with proper reduction scheme. 展开更多
关键词 Concatenated codes continuous phase Modulation (CPM) Soft Input Soft Output (SISO) Euclidean distance
下载PDF
Effect of droplet characteristics on liquid-phase distribution in spray zone of internal mixing air-mist nozzle
3
作者 Wei-li Wu Chang-gui Cheng +2 位作者 Yang Li Shi-fa Wei De-li Chen 《China Foundry》 SCIE EI CAS CSCD 2024年第2期185-196,共12页
In continuous casting production,droplet characteristics are important parameters for evaluating the nozzle atomization quality,and have a significant impact on the secondary cooling effect and the slab quality.In ord... In continuous casting production,droplet characteristics are important parameters for evaluating the nozzle atomization quality,and have a significant impact on the secondary cooling effect and the slab quality.In order to study the behavior of atomized droplets after reaching the slab surface and to optimize the spray cooling effect,the influence of droplet diameter and droplet velocity on the migration behavior of droplets in the secondary cooling zone was analyzed by FLUENT software.Results show that the droplets in the spray zone and on the slab surface are mainly concentrated in the center,thus,the liquid volume fraction in the center is higher than that of either side.As the droplet diameter increases,the region of high liquid volume fraction on the slab surface becomes wider,and the liquid phase distribution in the slab width direction becomes uneven.Although increasing the droplet velocity at the nozzle exit has little effect on droplet diffusion in the spray zone,the distribution becomes more uneven due to more liquid reaches the slab surface per unit time.A prediction formula of the maximum water flow rate on the slab surface for specific droplet characteristics was proposed based on dimensionless analysis and validated by simulated data.A nozzle spacing of 210 mm was recommended under the working conditions in this study,which ensures effective coverage of the spray water over the slab surface and enhances the distribution uniformity of water flow rate in the transverse direction. 展开更多
关键词 continuous casting secondary cooling zone internal mixing air-mist nozzle droplet characteristics liquid phase distribution water flow rate
下载PDF
Modelling of Phase Transformation of Plain Carbon Steels during Continuous Cooling
4
作者 YutuoZHANG ChunliMO +1 位作者 DianzhongLI YiyiLI 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2003年第3期262-264,共3页
A model based on Avrami equation and Scheil's additivity rule was proposed to simulate the phase transformation in plain carbon steels during continuous cooling in hot strip mill. In this model, a wide range of co... A model based on Avrami equation and Scheil's additivity rule was proposed to simulate the phase transformation in plain carbon steels during continuous cooling in hot strip mill. In this model, a wide range of composition, cooling rate, primary austenite grain size and retained strain has been taken into account. It can be used to calculate the phase fraction transformed at different temperatures during continuous cooling. The phase equilibrium and transformation starting temperature can be determined by using Thermo-Calc and DICTRA. The simulated results containing the transformation at starting and finishing temperatures, Ae1, Ae3 and the maximum volume fraction for Q235B, were obtained. The calculated phase volume fractions are in good agreement with .the experimental results. 展开更多
关键词 phase transformation continuous cooling Plain carbon steels
下载PDF
Improved dichotomous search frequency offset estimator for burst-mode continuous phase modulation
5
作者 翟文超 李赞 +1 位作者 司江勃 柏均 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第11期584-591,共8页
A data-aided technique for cartier frequency offset estimation with continuous phase modulation (CPM) in burst- mode transmission is presented. The proposed technique first exploits a special pilot sequence, or trai... A data-aided technique for cartier frequency offset estimation with continuous phase modulation (CPM) in burst- mode transmission is presented. The proposed technique first exploits a special pilot sequence, or training sequence, to form a sinusoidal waveform. Then, an improved dichotomous search frequency offset estimator is introduced to determine the frequency offset using the sinusoid. Theoretical analysis and simulation results indicate that our estimator is noteworthy in the following aspects. First, the estimator can operate independently of timing recovery. Second, it has relatively low outlier, i.e., the minimum signal-to-noise ratio (SNR) required to guarantee estimation accuracy. Finally, the most important property is that our estimator is complexity-reduced compared to the existing dichotomous search methods: it eliminates the need for fast Fourier transform (FFT) and modulation removal, and exhibits faster convergence rate without accuracy degradation. 展开更多
关键词 frequency offset estimation Cramer-Rao bound dichotomous search continuous phase modulation
下载PDF
Effect of Continuous Phase Viscosity on Membrane Emulsification
6
作者 王志 王世昌 +1 位作者 Volker Schroeder Helmar Schubert 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2000年第2期108-112,共5页
Oil-in-water(o/w) emulsions were produced with a membrane emulsification system. The effect of the continuous phase viscosity on the emulsification was studied. The theoretical analyses show that the continuous phase ... Oil-in-water(o/w) emulsions were produced with a membrane emulsification system. The effect of the continuous phase viscosity on the emulsification was studied. The theoretical analyses show that the continuous phase viscosity influences not only the flow field of the continuous phase but also the interfacial tension. The droplet size distribution and disperse phase flux for different continuous phase viscosity were investigated experimentally at constant wall shear stress and constant volume flow rate of the continuous phase respectively. 展开更多
关键词 membrane emulsification VISCOSITY continuous phase
下载PDF
Multi-Branch Fractional Multi-Bit Differential Detection of Continuous Phase Modulation with Decision Feedback
7
作者 Jinhua Sun Xiaojun Wu 《Communications and Network》 2011年第1期23-30,共8页
Differential detection of continuous phase modulation suffers from significant intersymbol interference. To reduce bit error rate, multi-branch fractional multi-bit differential detection (MFMDD) with decision feed-ba... Differential detection of continuous phase modulation suffers from significant intersymbol interference. To reduce bit error rate, multi-branch fractional multi-bit differential detection (MFMDD) with decision feed-back is proposed. By introducing decision feedback in multi-bit differential detected signals, severe inter-symbol interference can be removed. Simulation results show that the proposed structure can greatly im-proves the performance compared with MFMDD without decision feedback, and the performance of 9 FMDD is very near to the performance of the coherent detection. 展开更多
关键词 continuous phase Modulation DIFFERENTIAL DETECTION FRACTIONAL Multi-Bit DIFFERENTIAL DETECTION Decision Feedback
下载PDF
THE TEMPERATURE ANALYSIS OF THE BILLET WITH PHASE CHANGE DURING CONTINUOUS CASTING
8
作者 赵兴华 陈小弟 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1994年第2期109-118,共10页
In this paper,the problem of 3-D steady heat conduction including the influenceof phase change on billets is turned into the 2-D transient problem by a suitable transformation technique. The effective specific heat ha... In this paper,the problem of 3-D steady heat conduction including the influenceof phase change on billets is turned into the 2-D transient problem by a suitable transformation technique. The effective specific heat has been employed to substitutefor the effect of the phase ceange.The computational formulation of finite element has been presented. And the careful disposal of the phase change region has also beengiven. 展开更多
关键词 continuous casting.phase change.temperature field
下载PDF
Dynamic Rangefinding Device Using Amplitude-Modulated Continuous UltrasonicWave+
9
作者 华宏 王涌天 徐彤 《Journal of Beijing Institute of Technology》 EI CAS 1998年第1期55-61,共7页
Aim To develop a high speed and high resolution dynamic rangefinding device for the measurement of large distances.Methods The device was comprised of an ultrasonic transmitter and a receiver,and a receiver , and a co... Aim To develop a high speed and high resolution dynamic rangefinding device for the measurement of large distances.Methods The device was comprised of an ultrasonic transmitter and a receiver,and a receiver , and a continuous ultrasonic wave amplitude-modulated by a low- frequency acoustic signal was used. The rangefinding was achieved by detecting the phase difference between the transmitted and received ultrasonic signals. The design principle. hard- ware implementation , experimental results and performance analysis of the device are included. Results and Conclusion Experiments show that the accuracy of the device are included. within 1.5m while its dynamic data update rate can be up to 40kHz. 展开更多
关键词 position tracker rangefinding continuous ultrasonic wave phase shift
下载PDF
Evolution of microstructural and mechanical properties of AISI 316 during continuous drive friction welding process 被引量:1
10
作者 Ammar Jabbar Hassan Taoufik Boukharouba +2 位作者 Djamel Miroud Nacer-Eddine Titouche Salah Ramtani 《China Welding》 CAS 2020年第4期7-12,共6页
The aim of present study is introducing a method by subdividing friction welding phases into three steps according to the temperature change during continuous drive friction welding operation. Thermal curve allowable ... The aim of present study is introducing a method by subdividing friction welding phases into three steps according to the temperature change during continuous drive friction welding operation. Thermal curve allowable subdividing of the friction welding phase's time into three distinct periods, while the microstructure evolution during friction welding goes through three different situations. The effects of three distinct periods were achieved by macro-microscopy, microhardness HV_(0.1), tensile tests and scanning electronic microscopy(SEM).The results clearly show that the microstructure during the friction phase goes through three completely different situations which mechanically influenced on microstructure, tensile strength and ductility of the welded joint. 展开更多
关键词 continuous drive friction welding friction welding phase steps tensile strength MICROHARDNESS microstructure
下载PDF
Effects of correlative factors on the interdendritic melt flow brought by the bulge in continuous casting slabs 被引量:3
11
作者 Shuying Chen Guowei Chang +1 位作者 Jianzhong Wang Chunjing Wu 《Journal of University of Science and Technology Beijing》 CSCD 2008年第4期407-411,共5页
The effects of various factors on the flow speed of interdendritic melt were analyzed in detail in the process of continuous casting slabs. When the solid-liquid interface bends periodically, the expression of solute ... The effects of various factors on the flow speed of interdendritic melt were analyzed in detail in the process of continuous casting slabs. When the solid-liquid interface bends periodically, the expression of solute distribution in the columnar crystal zone was deduced, and the quantitative calculation was also made. The results show that the bulge and the interdendritic spacing are responsible for the flow speed of interdendritic melt. At the initial stage of solidification the bulge operates, and at the final stage the interdendritic spacing operates. The experimental results of macrosegregation in the slabs validated the calculated results of the flow speed of interdendritic melt, which shows that the calculated results are basically consistent with the experimental ones. 展开更多
关键词 continuous casting two-phase region melt flow MACROSEGREGATION
下载PDF
Continuous Flow Reactor for Hydroxylation of Benzene to Phenol by Hydrogen Peroxide
12
作者 Li Zhang Hui-hui Liu +1 位作者 Gui-ying Li Chang-wei Hu 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2012年第5期585-591,I0004,共8页
The direct hydroxylation of benzene to phenol catalyzed by activated carbon-supported Fe (Fe/AC) in acetonitrile using H2O2 as the oxidant was studied in a continuous flow reactor. Results showed that the continuous... The direct hydroxylation of benzene to phenol catalyzed by activated carbon-supported Fe (Fe/AC) in acetonitrile using H2O2 as the oxidant was studied in a continuous flow reactor. Results showed that the continuous operation could obtain high phenol yield of 28.1%, coupled with the turnover frequency of 3 h^-1, and high selectivity of 98% under mild condition. The catalyst was characterized by N2 adsorption/desorption, Boehm titration, X-ray photoelectron spectra, and Fourier transform infrared spectroscopy. It was observed that iron may interact with the carboxyl group forming iron-carboxylate like species, which act as the active phase. The apparent activation energy obtained by fitting an Arrhenius model to the experimental data was 13.4 kJ/mol. The reaction order was calculated to be about i, 0.2 for benzene and 0.7 for H202. 展开更多
关键词 continuous flow reactor HYDROXYLATION Activated carbon Iron-carboxylate Active phase Activation energy
下载PDF
EFFECTS OF PHASE CONTINUITY ON RHEOLOGY OF TWO-PHASE ROCKS: A CONTINUUM MECHANICL MODEL
13
作者 JI Shao cheng (Department des Genis Civil, Geologique et des Mines, ecole Polytechnique de Montreal, P.O. Box 6079, Station Centre Ville, Montreal (Quebec), H3C 3A7, Canada) 《Geotectonica et Metallogenia》 2001年第1期51-64,共14页
Based on continuum mechanics, we have developed a model for semi quantitative estimating effects of phase continuity on flow strength of two phase rocks including partially melted or crystallized rocks. Calculations o... Based on continuum mechanics, we have developed a model for semi quantitative estimating effects of phase continuity on flow strength of two phase rocks including partially melted or crystallized rocks. Calculations of the bulk flow strength of composite rocks as functions of the volume fraction, geometrical shape and continuity of the constitutive phases involve in numerically solving two non linear equations and thus are easy to be performed. The model has been justified by a good agreement between the predicted and measured results on diabase (64% clinopyroxene and 36% plagioclase) in the range of experimental temperatures and strain rates. It is believed that the present model could provide an approximate estimate for the rheological evolution of magmatic rocks during their life cycle of melting crystallization deformation. 展开更多
关键词 phase continuITY TWO-phase ROCKS RHEOLOGY continuUM mechanical model
下载PDF
A Liquid Chromatography Assay for the Simultaneous Quantification of Piperacillin and Ciprofloxacin in Human Plasma and Dialysate in Critically Ill Patients Undergoing Continuous Renal Replacement Therapy
14
作者 Florian Scheer Irene Kramer 《International Journal of Analytical Mass Spectrometry and Chromatography》 2014年第2期43-51,共9页
Piperacillin/tazobactam and ciprofloxacin are often used in combination as initial empiric anti-biotic therapy in critical ill patients. Especially in patients undergoing continuous renal replacement therapy (CRRT) th... Piperacillin/tazobactam and ciprofloxacin are often used in combination as initial empiric anti-biotic therapy in critical ill patients. Especially in patients undergoing continuous renal replacement therapy (CRRT) the pharmacokinetics of antimicrobial agents can be highly variable. In order to avoid under- or overdosage of antibiotics therapeutic drug monitoring (TDM) is highly re-commendable. Based on two known HPLC assays for piperacillin a new method in combination with solid phase extraction (SPE) for the simultaneous determination of piperacillin and ciprofloxacin was developed. Method validation was performed according to the EMA guideline on validation of bioanalytical methods. The HPLC column used was a Perfect Bond ODS-HD C18 analytical column (100 mm × 4.6 mm i.d., particle size 5 μm), equipped with a guard column (10 mm × 4.6 mm, particle size 5 μm) containing the same packing material. Detection wavelength was set at 228 nm for piperacillin and benzylpenicillin was used as internal standard (IS). Ciprofloxacin was determined at two wavelengths (280 nm, 315 nm). This newly developed HPLC method in combination with SPE-extraction allows an accurate, precise, specific and efficient determination of piperacillin and ciprofloxacin in biological matrices. Results allow the calculation of all relevant pharmacokinetic data for critically ill patients undergoing CRRT and the optimization of dosing and TDM. 展开更多
关键词 PIPERACILLIN CIPROFLOXACIN Solid phase Extraction(SPE) HPLC-UV continuous Renal Replacement Therapy(CRRT) Therapeutic Drug Monitoring(TDM)
下载PDF
Transforming Molecules into Medicines: Role of CDMOS in Phase-Appropriate Technology Transfers in Advancing Pharmaceutical Innovation
15
作者 Kishore Kumar Hotha 《Advances in Chemical Engineering and Science》 2023年第3期203-223,共21页
CDMOs are emerging as critical drivers of innovation within the pharmaceutical and biotech industries. As the pharmaceutical industry continues to evolve, we can expect to see CDMOs play an increasingly important role... CDMOs are emerging as critical drivers of innovation within the pharmaceutical and biotech industries. As the pharmaceutical industry continues to evolve, we can expect to see CDMOs play an increasingly important role in drug development and manufacturing. Many companies within these sectors are now leveraging the expertise of CDMOs through technology transfers to foster innovation and enhance the development of new drug products. In the extensive field of drug development, technology transfer plays a crucial role at multiple stages, ranging from preclinical phases to commercialization. By working closely with drug developers, CDMOs can ensure that technologies are transferred seamlessly between phases of drug development, allowing for a more efficient and cost-effective development process. CDMOs also bring a wealth of experience in various areas of drug development, including process development, analytical testing, quality control, and manufacturing. This expertise, combined with a focus on innovation, can help drug developers to overcome technical challenges and optimize their drug development programs. CDMOs can provide drug developers with various manufacturing capabilities, from small-scale clinical trials to large-scale commercial production. This flexibility allows drug developers to focus on their core competencies while relying on CDMOs to provide the necessary infrastructure and support for drug manufacturing. The critical role of CDMOs in advancing pharmaceutical innovation in phase-appropriate technology transfer where there will be a lot of effort and patience with strong technical expertise is required. This article explores the various types of Technology transfer from preclinical to commercial stages and successful strategies to foster innovation. 展开更多
关键词 Technology Transfer CDMO INNOVATION PRECLINICAL GMP phase Appropriate Method Development phase-1 Commercial Manufacturing continuous Improvement Lifecycle Management
下载PDF
Practical Security of the Continuous-Variable Quantum Key Distribution with Locally-Generated Local Oscillators
16
作者 Biao Huang Yongjun Zhu +2 位作者 Pu Tang Yongmei Huang Zhenming Peng 《Journal of Applied Mathematics and Physics》 2019年第11期2751-2759,共9页
Continuous-variable quantum key distribution (CVQKD) with the local local oscillator (LLO) is confronted with new security problems due to the reference pulses transmitted together with quantum signals over the insecu... Continuous-variable quantum key distribution (CVQKD) with the local local oscillator (LLO) is confronted with new security problems due to the reference pulses transmitted together with quantum signals over the insecure quantum channel. In this paper, we propose a method of phase attack on reference pulses of the LLO-CVQKD with time-multiplexing. Under this phase attack, the phase drifts of reference pulses are manipulated by eavesdroppers, and then the phase compensation error is increased. Consequently, the secret key rate is reduced due to the imperfect phase compensation for quantum signals. Based on the noise model of imperfect phase compensation, the practical security of LLO-CVQKD under phase attack is analyzed. The simulation results show that the practical security is reduced due to the phase attack, yet it is still tight when system parameters are estimated by training signals. 展开更多
关键词 continuous-Variable Quantum Key Distribution Local Oscillator Reference Pulse PRACTICAL SECURITY phase Attack
下载PDF
个体化频带滑动窗特征的轻度认知障碍诊断研究
17
作者 李昕 屈中杰 +2 位作者 李梓澎 尹立勇 苏芮 《电子测量与仪器学报》 CSCD 北大核心 2024年第2期182-189,共8页
轻度认知障碍(MCI)是老年性痴呆诊断的关键阶段,脑电(EEG)信号特征可以反映MCI患者的认知状态,帮助实现早期诊断。现有研究在EEG特征提取过程中,针对脑电各节律,大多采用固定的时间窗完成分段处理,忽略了不同节律的特征差异,从而影响诊... 轻度认知障碍(MCI)是老年性痴呆诊断的关键阶段,脑电(EEG)信号特征可以反映MCI患者的认知状态,帮助实现早期诊断。现有研究在EEG特征提取过程中,针对脑电各节律,大多采用固定的时间窗完成分段处理,忽略了不同节律的特征差异,从而影响诊断效果。针对该问题,本文提出了一种新的组合滑动窗优化算法,该算法通过迭代振幅调整傅里叶变换(IAAFT)对零模型的构建方法进行了改进,以此得到评估大脑动态特性指标KPLI,通过对EEG各频段信号采取多种滑动窗组合,并以KPLI指标引导,得到适合不同频段的最佳滑动窗组合。在最佳滑动窗组合基础上,对各频段组合提取相位滞后指数(PLI),进行连续小波变换(CWT)特征,通过ResNet-MLP双通道分类网络实现MCI诊断。结果显示,使用个性化组合频段滑动窗对88名受试者(32名MCI患者,36名阿尔茨海默症患者以及20名正常对照组)实现了诊断分类,得到了82.2%的分类准确率,比固定窗的分类提高了10%(得到了72.2%的分类准确率)。结果表明,基于个体化脑电节律特征组合能够更好提取MCI的特征,提高轻度认知障碍诊断的正确率与特异性,是一种有效的脑电特征提取方法。 展开更多
关键词 滑动窗 零模型 连续小波变换 相位滞后指数
下载PDF
萃余水相中酸和铀的连续测量方法
18
作者 陈强 董彦霞 +2 位作者 张慧妍 王扬 陈福平 《铀矿冶》 CAS 2024年第3期56-62,共7页
萃余水相中的酸浓度、铀浓度一般需分开检测,操作步骤繁琐,工作量大。本研究建立了连续测量萃余水相中酸浓度和铀浓度的新方法:先以强碱为滴定剂,通过指示剂的变色指示滴定终点,检测酸浓度;再加入硫酸和偶氮胂Ⅲ溶液,使溶液显色,在650 n... 萃余水相中的酸浓度、铀浓度一般需分开检测,操作步骤繁琐,工作量大。本研究建立了连续测量萃余水相中酸浓度和铀浓度的新方法:先以强碱为滴定剂,通过指示剂的变色指示滴定终点,检测酸浓度;再加入硫酸和偶氮胂Ⅲ溶液,使溶液显色,在650 nm处测量显色溶液的吸光度。结果显示,酸浓度测量的精密度为1.53%,示值误差为1.69%;铀质量浓度测量精密度为1.13%,示值误差为1.52%。在实际水样测量中,本方法和实验室现行方法测量数据基本一致,酸浓度测量的加标回收率为97.0%~102.5%,铀质量浓度测量的加标回收率为97.0%~102.0%,本方法可准确、快速、连续监测萃余水相中的酸浓度和铀浓度。 展开更多
关键词 萃余水相 余酸 酸碱滴定法 偶氮胂Ⅲ分光光度法 连续测量
下载PDF
宽带遥测网络中基于信道估计误差补偿的均衡算法
19
作者 王乐 吴胥岑 《电讯技术》 北大核心 2024年第9期1444-1449,共6页
随着遥测网络数据量的增加,传输信道的多径衰落严重影响接收性能。盲均衡算法实现结构简单,但仅在平衰落信道下提供优良的均衡性能。数据辅助的均衡算法能够抗深度衰落,但存在均衡误差较大的问题。针对上述两类算法的限制,利用数据辅助... 随着遥测网络数据量的增加,传输信道的多径衰落严重影响接收性能。盲均衡算法实现结构简单,但仅在平衰落信道下提供优良的均衡性能。数据辅助的均衡算法能够抗深度衰落,但存在均衡误差较大的问题。针对上述两类算法的限制,利用数据辅助抗衰落的特点,结合盲均衡简单的实现结构并进一步补偿信道估计误差,提出了数据辅助和恒模准则盲均衡联合均衡算法,用于提升整体均衡的性能。通过以遥测网络标准中的成形偏移四相相移键控(Shaped Offset Quadrature Phase Shift Key,Telemetry Group version,SOQPSK-TG)为调制信号搭建系统仿真,结果表明该混合算法优于传统基于数据辅助均衡算法和盲均衡算法,能够提供至少3 dB的误码率解调增益。 展开更多
关键词 遥测网络 联合均衡 信道估计 连续相位调制
下载PDF
Fe-3%Si合金薄带连铸板热处理过程层状异构组织演变的相场模拟研究
20
作者 杨玉芳 胡晋龙 +1 位作者 刘永博 王明涛 《材料导报》 EI CAS CSCD 北大核心 2024年第11期229-235,共7页
本研究基于Fe-3%Si合金铸轧板材组织特征,构建了不同类型柱状晶/等轴晶层状异构组织相场模型,实现了界面曲率为驱动力的情况下层状异构组织的高温粗化过程模拟,量化分析了层状异构特征对铸轧组织演化过程的影响规律。研究表明,由于晶粒... 本研究基于Fe-3%Si合金铸轧板材组织特征,构建了不同类型柱状晶/等轴晶层状异构组织相场模型,实现了界面曲率为驱动力的情况下层状异构组织的高温粗化过程模拟,量化分析了层状异构特征对铸轧组织演化过程的影响规律。研究表明,由于晶粒长径比对晶粒尖端曲率的影响,当初始状态下柱状晶长径比较高时,在界面曲率的驱动下最终会形成等轴化的多晶组织;反之则等轴化程度减小。明确了不同类型异构组织演化特征,相同退火时间下组织的等轴化程度受其层状异构特征的影响,这一现象的本质是等轴晶通过自身演化引起柱状晶两端曲率变化,诱发柱状晶间的相互“吞噬”并发生等轴化,柱状晶则在部分结构的组织中生长至带钢表面后停止生长,最终保持柱状特征。本研究进一步加深了对铸态薄带中初始凝固组织在后续热处理时演化过程的认识,对硅钢制备工艺优化具有重要的理论指导意义和实际应用价值。 展开更多
关键词 Fe-3%Si合金 薄带连铸 相场模拟 组织演化
下载PDF
上一页 1 2 60 下一页 到第
使用帮助 返回顶部