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Trends of alkaline phosphatase to prealbumin ratio in patients with hepatitis B linked to hepatocellular carcinoma development
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作者 Wen-Chong Zhen Jing Sun +8 位作者 Xue-Ting Bai Qian Zhang Zi-Han Li Yi-Xin Zhang Rong-Xuan Xu Wei Wu Zhi-Han Yao Chun-Wen Pu Xiao-Feng Li 《World Journal of Gastroenterology》 SCIE CAS 2025年第2期42-51,共10页
BACKGROUND Chronic hepatitis B often progresses silently toward hepatocellular carcinoma(HCC),a leading cause of mortality worldwide.Early detection of HCC is crucial,yet challenging.AIM To investigate the role of dyn... BACKGROUND Chronic hepatitis B often progresses silently toward hepatocellular carcinoma(HCC),a leading cause of mortality worldwide.Early detection of HCC is crucial,yet challenging.AIM To investigate the role of dynamic changes in alkaline phosphatase to prealbumin ratio(APR)in hepatitis B progression to HCC.METHODS Data from 4843 patients with hepatitis B(January 2015 to January 2024)were analyzed.HCC incidence rates in males and females were compared using the log-rank test.Data were evaluated using Kaplan–Meier analysis.The Linear Mixed-Effects Model was applied to track the fluctuation of APR levels over time.Furthermore,Joint Modeling of Longitudinal and Survival data was employed to investigate the temporal relationship between APR and HCC risk.RESULTS The incidence of HCC was higher in males.To ensure the model’s normality assumption,this study applied a logarithmic transformation to APR,yielding ratio.Ratio levels were higher in females(t=5.26,P<0.01).A 1-unit increase in ratio correlated with a 2.005-fold higher risk of HCC in males(95%CI:1.653-2.431)and a 2.273-fold higher risk in females(95%CI:1.620-3.190).CONCLUSION Males are more prone to HCC,while females have higher APR levels.Despite no baseline APR link,rising APR indicates a higher HCC risk. 展开更多
关键词 Alkaline phosphatase to prealbumin ratio Chronic hepatitis B patients Hepatocellular carcinoma Retrospective cohort study Linear Mixed-Effect mode Joint modelling of Longitudinal and Survival data
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Application of empirical mode decomposition based energy ratio to vortex flowmeter state diagnosis 被引量:4
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作者 孙志强 张宏建 《Journal of Central South University》 SCIE EI CAS 2009年第1期154-159,共6页
To improve the measurement performance, a method for diagnosing the state of vortex flowmeter under various flow conditions was presented. The raw sensor signal of the vortex flowmeter was adaptively decomposed into i... To improve the measurement performance, a method for diagnosing the state of vortex flowmeter under various flow conditions was presented. The raw sensor signal of the vortex flowmeter was adaptively decomposed into intrinsic mode functions using the empirical mode decomposition approach. Based on the empirical mode decomposition results, the energy of each intrinsic mode function was extracted, and the vortex energy ratio was proposed to analyze how the perturbation in the flow affected the measurement performance of the vortex flowmeter. The relationship between the vortex energy ratio of the signal and the flow condition was established. The results show that the vortex energy ratio is sensitive to the flow condition and ideal for the characterization of the vortex flowmeter signal. Moreover, the vortex energy ratio under normal flow condition is greater than 80%, which can be adopted as an indicator to diagnose the state of a vortex flowmeter. 展开更多
关键词 flow state diagnosis energy ratio vortex flowmeter empirical mode decomposition
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Effects of Geometric Configurations on the Performance of Reverse Flow Diverters in Reverse Flow Mode 被引量:1
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作者 徐聪 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2012年第5期856-862,共7页
The reverse flow diverter (RFD) consisting of a nozzle and a diffuser is a key component in pneumatic pulse jet pumps. We investigated the effects of suction gap and diffuser configurations on RFD performance during t... The reverse flow diverter (RFD) consisting of a nozzle and a diffuser is a key component in pneumatic pulse jet pumps. We investigated the effects of suction gap and diffuser configurations on RFD performance during the reverse flow mode. Three suction gap configurations were examined: (1) an axisymmetrical cylinder, (2) a cuboid whose bottom plane had no half-circle groove and was level with the diffuser entrance lower border, and (3) a cuboid with a half-circle groove on the bottom plane. Among them, the second one resulted in the highest RFD pumping capacity. The effect of receiver presence before the diffuser was also examined. RFD pumping efficiency was found to be enhanced in the presence of a receiver before the diffuser when the suction gap length is small and the jet outlet velocity at the nozzle exit is high enough. Based on experimental data, a dimensionless performance curve of the suction factor q versus the ratio of Euler numbers in sections out-out and 0-0 Eu out /Eu 0 was derived. This curve is insensitive to suction gap configurations. 展开更多
关键词 reverse flow diverter suction gap RECEIVER nozzle area ratio reverse flow mode
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Influence of the column-to-beam flexural strength ratio on the failure mode of beam-column connections in RC frames 被引量:1
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作者 Gong Maosheng Zuo Zhanxuan +2 位作者 Sun Jing He Riteng Zhao Yinan 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2021年第2期441-452,共12页
The column-to-beam flexural strength ratio(CBFSR)has been used in many seismic codes to achieve the strong column-weak beam(SCWB)failure mode in reinforced concrete(RC)frames,in which plastic hinges appear earlier in ... The column-to-beam flexural strength ratio(CBFSR)has been used in many seismic codes to achieve the strong column-weak beam(SCWB)failure mode in reinforced concrete(RC)frames,in which plastic hinges appear earlier in beams than in columns.However,seismic investigations show that the required limit of CBFSR in seismic codes usually cannot achieve the SCWB failure mode under strong earthquakes.This study investigates the failure modes of RC frames with different CBFSRs.Nine typical three-story RC frame models with different CBFSRs are designed in accordance with Chinese seismic codes.The seismic responses and failure modes of the frames are investigated through time-history analyses using 100 ground motion records.The results show that the required limit of the CBFSR that guarantees the SCWB failure mode depends on the beam-column connection type and the seismic intensity,and different types of beam-column connections exhibit different failure modes even though they are designed with the same CBFSR.Recommended CBFSRs are proposed for achieving the designed SCWB failure mode for different types of connections in RC frames under different seismic intensities.These results may provide some reference for further revisions of the SCWB design criterion in Chinese seismic codes. 展开更多
关键词 strong column-weak beam column-to-beam flexural strength ratio reinforced concrete frame structure beam-column connection failure mode
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High common mode rejection ratio InP 90°optical hybrid in ultra-broadband at 60 nm with deep-rigded waveguide based on×4 MMI coupler 被引量:1
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作者 Zi-Qing Lu Qin Han +3 位作者 Han Ye Shuai Wang Feng Xiao Fan Xiao 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第5期265-272,共8页
An InP optical 90°hybrid based on a×4 MMI coupler with a deep ridged waveguide is designed and fabricated.The working principle of the 90°hybrid is systematically introduced.Three-dimensional beam ropag... An InP optical 90°hybrid based on a×4 MMI coupler with a deep ridged waveguide is designed and fabricated.The working principle of the 90°hybrid is systematically introduced.Three-dimensional beam ropagation method(3D BPM)is used to optimize the structure parameters of the 90°hybrid.The designed compact structure is demonatrated to have a low excess loss less than-0.15 dB,a high common mode rejection ratio better than 40 dB,and a low relative phase deviation less than±2.5°.The designed hybrid is manufactured on a sandwitched structure deposited on an InP substrate.The measured results show that the common mode rejection ratios are larger than 20 dB in a range from 1520 nm to 1580 nm.The phase deviations are less than±5°in a range from 1545 nm to 1560 nm and less than±7°across the C band.The designed 90°optical hybrid is suitable well for realizing miniaturization,high-properties,and high bandwidth of coherent receiver. 展开更多
关键词 90°hybrid ×4 MMI coupler deep ridge high common mode rejection ratio
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StudyonMathematicalModeofQuantification Performance-to-Price Ratio
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作者 裴兰华 史德战 王冠 《科技经济市场》 2007年第8期40-41,共2页
Nowadays, consumers often compare the same kind of commodities and decide what to pick out when they purchase merchandise including the service. The paper discusses the mathematical mode of quantification performance-... Nowadays, consumers often compare the same kind of commodities and decide what to pick out when they purchase merchandise including the service. The paper discusses the mathematical mode of quantification performance-to-price ratio according to which product can be made in order to increase the competitiveness in the market. 展开更多
关键词 performance-to-price ratio quantification MATHEMATICAL mode
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Experimental Investigation of Multi-Mode Vortex-Induced Vibration of Flexible Risers with Different Mass Ratios
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作者 WANG Yu LOU Min +3 位作者 REN Xiao-hui LIANG Wei-xing LI Xiang DANG Peng-bo 《China Ocean Engineering》 SCIE EI CSCD 2023年第1期1-15,共15页
Experiments were conducted on risers with different mass ratios to study the effect of mode conversion and spanwise correlation. The slenderness ratio of the riser model was set as 169, and the Reynolds numbers are 16... Experiments were conducted on risers with different mass ratios to study the effect of mode conversion and spanwise correlation. The slenderness ratio of the riser model was set as 169, and the Reynolds numbers are 1600-14400. The dynamic responses of riser models versus reduced velocity were analyzed, and the spanwise displacement, frequency,and trajectory of the mode conversion from the lower to the higher mode were explored. The results revealed that the riser model with a higher mass ratio excites a higher number of modes. The conversion region of multi-mode competition exists and narrows with the increasing mass ratio. Mode conversion is continuous and manifests as the transmission of peaks and troughs in mode shape: the peaks and troughs of mode shape move up in the mode stable development region and move down in the mode conversion region. The single-mode dominating vibration exhibits a standing wave feature, and the traveling wave feature is significant in the mode conversion region. Furthermore, the frequency jump is always transmitted from the trough to the peak of the mode shape, and finally, all the axial positions vibrate at the same frequency. The trajectory in the mode conversion region deviates from the 8-shape and recovers the standard8-shape at the middle and late stages of the mode stable development region. 展开更多
关键词 vortex-induced vibration dynamic response mode conversion mass ratio mode weight
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Effects of Finite Aspect Ratio and Noncircular Plasma Flux Surface on Electron Temperature Gradient Driven Modes
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作者 王英 高喆 《Plasma Science and Technology》 SCIE EI CAS CSCD 2008年第2期151-157,共7页
A gyrokinetic model with integral eigenmode equations is developed based on the local equilibrium of shaped tokamak plasmas. Effects of main geometric parameters (finite aspect ratio, elongation, triangularity, and S... A gyrokinetic model with integral eigenmode equations is developed based on the local equilibrium of shaped tokamak plasmas. Effects of main geometric parameters (finite aspect ratio, elongation, triangularity, and Shafranov shift gradient) on the electrostatic electron temper- ature gradient (ETG) driven modes are investigated numerically. It is found that the finite aspect ratio has a general stabilizing effect, while the elongation can be either stabilizing or destabilizing, depending on the poloidal wavelength of the mode and other parameters. It is shown that a low aspect ratio enhances the stabilizing effect of elongation, and weakens its destabilizing effect as well. 展开更多
关键词 electron temperature gradient modes shaped plasma finite aspect ratio noncircular flux surface elongation
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Operational Mode Identification Based on Sliding Time Window Method and Eigensystem Realization Algorithm
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作者 WANG Liang ZHANG Yan +1 位作者 CAI Yipeng NANGONG Zijun 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2019年第5期838-844,共7页
The identification result of operational mode is eurychoric while operational mode identification is investigated under ambient excitation,which is influenced by the signal size and the time interval.The operational m... The identification result of operational mode is eurychoric while operational mode identification is investigated under ambient excitation,which is influenced by the signal size and the time interval.The operational mode identification method,which is based on the sliding time window method and the eigensystem realization algorithm(ERA),is investigated to improve the identification accuracy and stability.Firstly,the theory of the ERA method is introduced.Secondly,the strategy for decomposition and implementation is put forward,including the sliding time window method and the filtration method of modes.At last,an example is studied,where the model of a cantilever beam is built and the white noise exciting is input.Results show that the operational mode identification method can realize the modes,and has high robustness to the signal to noise ratio and signal size. 展开更多
关键词 mode identification ROBUST eigensystem realization algorithm(ERA) operational mode damping ratio
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Effect of Strain Ratio on Fatigue Model of Ultra-fine Grained Pure Titanium
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作者 QIANG Meng YANG Xirong +1 位作者 LIU Xiaoyan LUO Lei 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2023年第5期1169-1178,共10页
The ultra-fine grained(UFG)pure titanium was prepared by equal channel angular pressing(ECAP)and rotary swaging(RS).The strain controlled low cycle fatigue(LCF)test was carried out at room temperature.The fatigue life... The ultra-fine grained(UFG)pure titanium was prepared by equal channel angular pressing(ECAP)and rotary swaging(RS).The strain controlled low cycle fatigue(LCF)test was carried out at room temperature.The fatigue life prediction model and mean stress relaxation model under asymmetrical stress load were discussed.The results show that the strain ratio has a significant effect on the low cycle fatigue performance of the UFG pure titanium,and the traditional Manson-coffin model can not accurately predict the fatigue life under asymmetric stress load.Therefore,the SWT mean stress correction model and three-parameter power curve model are proposed,and the test results are verified.The final research shows that the threeparameter power surface model has better representation.By studying the mean stress relaxation phenomenon under the condition of R≠-1,it is revealed that the stress ratio and the strain amplitude are the factors that significantly afiect the mean stress relaxation rate,and the mean stress relaxation model with the two variables is calculated to describe the mean stress relaxation phenomenon of the UFG pure titanium under different strain ratios.The fracture morphology of the samples was observed by SEM,and it was concluded that the final fracture zone of the fatigue fracture of the UFG pure titanium was a mixture of ductile fracture and quasi cleavage fracture.The toughness of the material increases with the increase of strain ratio at the same strain amplitude. 展开更多
关键词 ultra-fine grained pure titanium low cycle fatigue life model mean stress relaxation mode strain ratio fracture morphology
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Influence of Trailing-Edge Wear on the Vibrational Behavior of Wind Turbine Blades
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作者 Yuanjun Dai Xin Wei +2 位作者 Baohua Li Cong Wang Kunju Shi 《Fluid Dynamics & Materials Processing》 EI 2024年第2期337-348,共12页
To study the impact of the trailing-edge wear on the vibrational behavior of wind-turbine blades,unworn blades and trailing-edge worn blades have been assessed through relevant modal tests.According to these experimen... To study the impact of the trailing-edge wear on the vibrational behavior of wind-turbine blades,unworn blades and trailing-edge worn blades have been assessed through relevant modal tests.According to these experiments,the natural frequencies of trailing-edge worn blades-1,-2,and-3 increase the most in the second to fourth order,thefifth order increases in the middle,and thefirst order increases the least.The damping ratio data indi-cate that,in general,thefirstfive-order damping ratios of trailing-edge worn blades-1 and trailing-edge worn blades-2 are reduced,and thefirstfive-order damping ratios of trailing-edge worn blades-3 are slightly improved.The mode shape diagram shows that the trailing-edge worn blades-1 and-2 have a large swing in the tip and the blade,whereas the second-and third-order vibration shapes of the trailing edge-worn blade-3 tend to be improved.Overall,all these results reveal that the blade’s mass and the wear area are the main fac-tors affecting the vibration characteristics of wind turbine blades. 展开更多
关键词 Wind turbine modal test natural frequency damping ratio mode shape
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超声B-Mode Ratio对糖尿病患者颌下腺脂肪沉积的诊断效能
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作者 汪学梅 吴爽 +5 位作者 牛明佳 李建新 董艳超 刘德丰 陈燕生 袁坤 《计算机与数字工程》 2022年第2期247-250,366,共5页
为了对比评价超声B-mode ratio及MR-IP-OP两种检查方法对糖尿病患者颌下腺脂肪沉积的诊断效能。选取志愿者174人(糖尿病患者89人和健康志愿者85人),利用超声B-mode ratio技术和3D MR-IP-OP方法评估和检测颌下腺的脂肪含量。使用独立样本... 为了对比评价超声B-mode ratio及MR-IP-OP两种检查方法对糖尿病患者颌下腺脂肪沉积的诊断效能。选取志愿者174人(糖尿病患者89人和健康志愿者85人),利用超声B-mode ratio技术和3D MR-IP-OP方法评估和检测颌下腺的脂肪含量。使用独立样本t检验比较两组患者B-radio和MRI-IP-OP的FF值组间差异。采用受试者工作特征曲线(ROC)分析两种技术对颌下腺脂肪沉积的诊断效能。用Spear-man相关系数评价两组参数之间的相关性。糖尿病组的B-mode ratio值(1.337±0.128)明显高于正常组(0.917±0.138)。糖尿病组MR-IP-OP的FF值(21.88±7.86%)明显高于正常组(8.87±3.09%)。ROC曲线表明脂肪沉积评价中B-mode ratio和3D MR-IP-OP的曲线下面积(AUC)分别为0.860和0.909,超声B-mode ratio和3D MR-IP-OP方法获得的结果间有良好相关性(r=0.502,p<0.001)。超声B-mode ratio对颌下腺脂肪变性的诊断具有良好的诊断效能,可以替代MR-IP-OP检查技术,并且有很好的临床应用前景。 展开更多
关键词 B-mode ratio MR IP-OP 糖尿病 颌下腺 脂肪沉积
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MODES系统对贵州月气温、降水预测初步评估 被引量:6
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作者 白慧 高辉 +2 位作者 刘长征 毛炜峄 杜良敏 《沙漠与绿洲气象》 2016年第5期58-63,共6页
通过对2013年1月—2015年6月(MODES)发布的最优月预测产品在贵州省月平均气温距平和降水距平百分率的预测检验评估,发现MODES对全省平均气温有较好的预报,分析时段内预测与实况的相关系数为0.24,距平同号率为65.5%,且对气温偏高预测的... 通过对2013年1月—2015年6月(MODES)发布的最优月预测产品在贵州省月平均气温距平和降水距平百分率的预测检验评估,发现MODES对全省平均气温有较好的预报,分析时段内预测与实况的相关系数为0.24,距平同号率为65.5%,且对气温偏高预测的可参考性高于其对气温偏低的预测。相比于气温,MODES对降水预测能力较弱,参考性也相对较低,其中对贵州全省平均降水偏多趋势的预测技巧要优于对全省平均偏少趋势的预报技巧。逐站分析显示,MODES对贵州气温预测效果较好的地区在西部、北部和东部,对降水偏多的预测效果较好的地区位于除西北部和北部边缘地区外的其余大部地区。通过对MODES与预报员综合预报的结果评估发现,MODES月预测总体效果较预报员好,且稳定性高于预报员,可为预报员提供参考信息。 展开更多
关键词 多模式解释应用集成预测系统(modeS) 距平同号率 Ps评分 检验评估
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不同树种配置模式和郁闭度对桉树改造林土壤养分的影响
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作者 刘长德 刘梦瑶 +6 位作者 陈锦睿 胡文涛 田雪琴 赵鸿杰 罗霜 王洪梅 潘澜 《森林工程》 北大核心 2025年第1期86-99,共14页
由于桉树人工林种植模式基本为多代连栽的单一模式,导致了诸多生态学问题的出现。因此,确保人工桉树林能够实现长期、稳定的可持续经营,已成为人工桉树林栽培技术的热点问题。为实现这一目标,采取恰当的树种配置与适度的郁闭度是调整林... 由于桉树人工林种植模式基本为多代连栽的单一模式,导致了诸多生态学问题的出现。因此,确保人工桉树林能够实现长期、稳定的可持续经营,已成为人工桉树林栽培技术的热点问题。为实现这一目标,采取恰当的树种配置与适度的郁闭度是调整林分结构、增强土壤质量的有效方法。选取佛山市西岸林场6个桉树纯林样地进行改造,研究2种树种配置模式(A为5种山茶科树种,B为5种山茶科树种和2种落叶阔叶树种)和3种桉树郁闭度(Y1为0%,Y2为15%,Y3为30%)对土壤理化性质、酶活性和土壤化学计量比的影响。在不同树种配置模式中,B模式Y3样地3个土层(0~20、20~40、40~60 cm)的土壤毛管持水量、土壤毛管孔隙度和土壤孔隙比与0~20 cm土层的全氮、氮磷比(N∶P)、过氧化氢酶活性和脲酶活性显著高于A模式Y3样地(P<0.05)。在不同郁闭度中,A模式Y3样地3个土层的全磷、有效磷、速效钾、过氧化氢酶活性和脲酶活性显著高于Y1样地(P<0.05),且B模式Y3样地3个土层的有机碳、全氮、碱解氮、有效磷、过氧化氢酶活性和N∶P显著高于Y1样地(P<0.05)。综上所述,合适的树种配置模式和郁闭度有益于土壤养分和酶活性的提高,30%桉树郁闭度下山茶科树种与落叶阔叶树种的模式在华南地区的改造具有良好的应用前景。 展开更多
关键词 桉树 配置模式 郁闭度 土壤理化性质 土壤酶活性 土壤化学计量比
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High-speed polarization mode dispersion compensation in a 43-Gb/s RZ-DQPSK transmission system over 1200 km of standard single-mode fibre 被引量:3
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作者 田凤 张晓光 +3 位作者 翁轩 席丽霞 张阳安 张文博 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第8期143-149,共7页
This paper reports that the designed optical polarization mode dispersion compensator shows a good performance under the real-time variation of differential group delay, state of polarization and principal state of po... This paper reports that the designed optical polarization mode dispersion compensator shows a good performance under the real-time variation of differential group delay, state of polarization and principal state of polarization in a (40×43)-Gb/s dense-wavelength-multiplexing, 1200-km enhanced return-to-zero differential-quadrature-phase-shift- keying (RZ-DQPSK) system. The polarization mode dispersion tolerance of the system is improved by 26 ps using the optical polarization mode dispersion compensator. The short and long time stabilities are tested with the bit error ratio recorded. 展开更多
关键词 optical polarization mode dispersion compensator polarization mode dispersion toler-ance bit error ratio forward error correction
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Higher mode effects in hinged wall with BRBsin base-frame structures using distributed parameter models 被引量:1
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作者 Yang Xiaoyan Wu Jing +2 位作者 Pang Xixi Wang Qiang Zhang Meng 《Journal of Southeast University(English Edition)》 EI CAS 2020年第1期56-66,共11页
To investigate the effect of higher modes on the displacement and inner forces in HWBB(hinged wall with buckling-restrained braces in base)-frame structure,distributed parameter models for both the HWBB-hinged frame s... To investigate the effect of higher modes on the displacement and inner forces in HWBB(hinged wall with buckling-restrained braces in base)-frame structure,distributed parameter models for both the HWBB-hinged frame structure and the HWBB-MRF(moment resisting frame)structure are built.The hinged wall is simplified as a flexural beam.BRBs(bucking-restrained braces)are simplified to a rotational spring.MRF is simplified to a shear beam.Vibration equations of distributed parameter models are derived.Natural periods,natural modes of vibration,inner forces and displacements of the distributed parameter models are derived based on the vibration equations using numerical methods.The effect of the relative stiffness ratio and the rotational stiffness ratio on the higher mode effects is investigated.For elastic structures,the global displacement and shear in MRF are predominantly controlled by the first mode,while the shear and bending moment in the wall are significantly affected by higher mode effects.The effect of the yielding of BRB on the inner forces distribution in the HWBB-hinged frame is investigated.The results indicate that the first mode will no longer contribute to the inner forces and the contribution from higher modes to inner forces increases after the BRBs yield.Displacement is not sensitive to higher mode effects and it is controlled by the first mode after the BRBs yield.Parameter analysis demonstrates that the displacement amplitudes are reduced with the increase in the flexural stiffness of the wall before the flexural stiffness reaches a certain value.The first three periods decrease with the increase in the rotational stiffness.With the increase in the rotational stiffness ratio,the contribution from the first mode decreases while contributions from both the second mode and third mode increase. 展开更多
关键词 hinged wall higher mode effects flexural beam rotational spring rotational stiffness ratio
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An Analytical Theory of the Signal-to-Noise Ratio of Hall Plates with Four Contacts and a Single Mirror Symmetry 被引量:1
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作者 Udo Ausserlechner 《Journal of Applied Mathematics and Physics》 2018年第10期2032-2066,共35页
This work gives an analytical theory of the signal-to-thermal-noise ratio (SNR) of classical Hall plates with four contacts at small magnetic field. In contrast to previous works, the symmetry of the Hall plates is re... This work gives an analytical theory of the signal-to-thermal-noise ratio (SNR) of classical Hall plates with four contacts at small magnetic field. In contrast to previous works, the symmetry of the Hall plates is reduced to only a single mirror axis, whereby the average of potentials of the two output contacts off this mirror axis differs from the average of potentials at the two supply contacts on the mirror axis, i.e. the output common mode differs from 50%. Surprisingly, at fixed power dissipated in the Hall plate, the maximum achievable SNR is only 9% smaller for output common modes of 30% and 70% when compared to the overall optimum at output common modes of 50%. The theory is applied to Vertical Hall effect devices with three contacts on the top surface and one contact being the buried layer in a silicon BiCMOS process. Geometries are found with large contacts and only a moderate loss in SNR. 展开更多
关键词 HALL Plate Vertical HALL Effect Device Geometry Factor CONFORMAL Mapping Signal to Noise ratio SINGLE Mirror SYMMETRY Equivalent RESISTOR Circuit Common mode Potential
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Slip Suppression of Electric Vehicles Using Sliding Mode Control Method 被引量:1
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作者 Shaobo Li Tohru Kawabe 《Intelligent Control and Automation》 2013年第3期327-334,共8页
This paper presents a slip suppression controller using sliding mode control method for electric vehicles which aims to improve the control performance and the energy conservation by controlling the slip ratio of whee... This paper presents a slip suppression controller using sliding mode control method for electric vehicles which aims to improve the control performance and the energy conservation by controlling the slip ratio of wheel. In this method, a robust sliding mode controller against the model uncertainties is designed to obtain the maximum driving force by suppressing the slip ratio. The numerical simulations for one wheel model under variations in mass of vehicle and road condition are performed and demonstrated to show the effectiveness of the proposed method. 展开更多
关键词 SLIDING mode Control SLIP ratio Electric Vehicles ROBUSTNESS Energy CONSERVATION
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Fuzzy Sliding Mode Control Based on Longitudinal Force Estimation for Electro-mechanical Braking Systems using BLDC Motor 被引量:4
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作者 Xiaoyan Peng Mingfei Jia +2 位作者 Lei He Xiang Yu Yibin Lv 《CES Transactions on Electrical Machines and Systems》 2018年第1期142-151,共10页
This paper focuses on the controller design using fuzzy sliding mode control(FSMC)with application to electro-mechanical brake(EMB)systems using BLDC Motor.The EMB controller transmits the control signal to the motor ... This paper focuses on the controller design using fuzzy sliding mode control(FSMC)with application to electro-mechanical brake(EMB)systems using BLDC Motor.The EMB controller transmits the control signal to the motor driver to rotate the motor.The torque distribution of motors is studied in this paper actually.Firstly,the model of the EMB system is established.Then the state observer is developed to estimate the vehicle states including the vehicle velocity and longitudinal force.Due to the fact that the EMB system is nonlinear and uncertain,a FSMC strategy based on wheel slip ratio is proposed,where both the normal and emergency braking conditions are taken into account.The equivalent control law of sliding mode controller is designed on the basis of the variation of the front axle and rear axle load during the brake process,while the switching control law is adjusted by the fuzzy corrector.The simulation results illustrate that the FSMC strategy has the superior performance,better adaptability to various types of roads,and shorter braking distance,as compared to PID control and traditional sliding mode control technologies.Finally,the hardware-in-loop(HIL)experimental results have exemplified the validation of the developed methodology. 展开更多
关键词 BLDC Motor electro-mechanical brake fuzzy sliding mode control longitudinal force estimation hardware-in-loop experiments wheel slip ratio
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Study on the Application of UHVDC Hierarchical Connection Mode to Multi-infeed HVDC System 被引量:81
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作者 LIU Zhenya QIN Xiaohui +1 位作者 ZHAO Liang ZHAO Qingbo 《中国电机工程学报》 EI CSCD 北大核心 2013年第10期I0001-I0026,25,共26页
随着我国特高压交直流技术的广泛应用,多馈入直流集中落入受端负荷中心将是未来我国电网发展所面临的重要问题。为从电网结构上有效解决多馈入直流系统的问题,提出一种特高压直流分层接入交流电网的方式。研究分层接入方式直流多馈入... 随着我国特高压交直流技术的广泛应用,多馈入直流集中落入受端负荷中心将是未来我国电网发展所面临的重要问题。为从电网结构上有效解决多馈入直流系统的问题,提出一种特高压直流分层接入交流电网的方式。研究分层接入方式直流多馈入短路比计算方法的适用性,从理论上对比特高压直流不同接入方式下多馈入直流电网的系统特性,证明特高压直流分层接入方式有助于提高多馈入直流系统的电压支撑能力,引导潮流在1000kV与500kV层级间合理分布。结合国家电网规划,仿真验证了特高压直流分层接入方式的优势。 展开更多
关键词 多馈入直流输电系统 特高压直流输电 连接模式 应用 输电技术 电网发展 负荷中心 电网结构
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