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Microwave Absorption and Shielding Property of Composites with FeSiAl and Carbonous Materials as Filler

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Journal of Materials Science & Technology 2012年第10期28卷 913-919页

作者： Wenqiang Zhang yonggang xu Liming Yuan Jun Cai Deyuan Zhang Bionic and Micro/Nano/Bio Manufacturing Technology Research Center School of Mechanical Engineering and Au-tomationBeihang UniversityBeijing 100191~China

Silicone rubber composites filled with FeSiAI alloys and multi-walled carbon nanotubes （MWCNT）/graphite have been prepared for the first time by a coating process. The complex permittivity and permeability of the composites were measured with a vector network analyzer in a 1-4 GHz frequency range, and the DC electric conductivity was measured by a standard four-point contact method. These parameters were then used to calculate the reflection loss （RL） and shielding effectiveness （SE） of the composites. The results showed that the added MWCNT increased the permittivity and permeability of composites in the L-band, while the added graphite increased only the permittivity. The variation lies in the interactions between two carbonous absorbents. Addition of 1 wt% MWCNT enhanced the RL in the L-band （minimum -5.7 dB at 1 ram, -7.3 dB at 1.5 ram）, while the addition of graphite did not. Addition of MWCNT as well as graphite reinforced the shielding property of the composites （maximum SE 13.3 dB at 1 ram, 18.3 dB at 1.5 ram） owing to the increase of conductivity. The addition of these carbonous materials could hold the promise of enforcing the absorption and shielding property of the absorbers.

关键词： Absorbing materials Electromagnetic Reflection loss Shielding effectiveness

Effects of Multi-walled Carbon Nanotubes on the Electromagnetic Absorbing Characteristics of Composites Filled with Carbonyl Iron Particles

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Journal of Materials Science & Technology 2012年第1期28卷 34-40页

作者： yonggang xu Deyuan Zhang Jun Cai Liming Yuan Wenqiang Zhang Bionic and Micro/Nano/Bio Manufacturing Technology Research Center School of Mechanical Engineering and AutomationBeihang UniversityBeijing 100191China

The electromagnetic （EM） wave absorbing property of silicone rubber filled with carbonyl iron particles （CIPs） and multi-walled carbon nanotubes （MWCNTs） was examined. Absorbents including MWCNTs and spherical/ flaky CIPs were added to silicone rubber using a two-roll mixer. The complex permittivity and complex permeability were measured over the frequency range of 1-18 GHz. The two EM parameters were verified and the uniform dispersion of MWCNTs and ClPs was confirmed by comparing the measured reflection loss （RL） with the calculated one. As the MWCNT weight percent increased, the RL of the spherical CIPs/silicone rubber composites changed insignificantly. It was attributed to the random distribution of spherical ClPs and less content of MWCNTs. On the contrary, for composites filled with flaky ClPs the absorption bandwidth increased at thickness 0.5 mm （RL value lower than -5 dB in 8-18 GHz） and the absorption ratio increased at lower frequency （minimum -35 dB at 3.5 GHz）. This effect was attributed to the oriented distribution of flaky CIPs caused by interactions between the two absorbents. Therefore, mixing MWCNTs and flaky CIPs could achieve wider-band and higher-absorption ratio absorbing materials.

关键词： Absorbing materials Carbon nanotubes Carbonyl iron particles Composites Reflection loss

Effects of Particle Sizes on the Electromagnetic Property of Flaky FeSi Composites

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Acta Metallurgica Sinica(English Letters) 2013年第4期26卷 366-372页

作者： yonggang xu Liming YUAN Jun CAI Jianlu LV Deyuan ZHANG Bionic and Micro/Nano/Bio Manufacturing Technology Research Center School of Mechanical Engineering and AutomationBeihang University

Flaky FeSi absorbents with different size ranges were fabricated by sintering after mechanical milling process. X-ray diffraction （XRD） was used to analyze the particle crystal grain structure. The complex permittivity and permeability of FeSi/paraffin composites were measured in frequency of 2-12 GHz using a vector network analyzer, and the DC electric conductivity was measured by the standard four-point contact method, then microwave reflection loss （RL） and shielding effectiveness （SE） were calculated. It was obtained that c^-Fe appeared in the super-lattice diffraction peaks in XRD pattern. As the particles size decreased, the permittivity decreased due to the inferior microwave electrical conductivity and dielectric loss tangent, while the permeability increased due to the decrease of diameter-thickness ratio, which could be demonstrated in the comparison between the experiment and calculation results. When thickness is 1 mm, the composites with the smallest FeSi particles addition had a better absorbing property for the better impedance matching characteristic, and the minimum RL was -7.9 dB at 4.6 GHz. While the composites with larger FeSi particles addition had an excellent shielding property due to the higher permittivity, the SE value ranged from 15 dB to 30 dB at the frequency band.

关键词： FeSi alloy Absorbing property Shielding property Mechanical milling

Effect of environment humidity to radon measurement with SSNTD

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Nuclear Science and Techniques 2009年第4期20卷 228-230页

作者： HUO yonggang xu Peng ZHOU Chunlin YANG Feng Xi＇an Research Institute of Hi-Tech Xi ＇an 710025 China

For a passive radon detector of Solid State Nuclear Track Detector(SSNTD),the measurement results can be affected under an environment of high *** order to correct this kind of measurement errors,experiments in normal radon laboratory were *** track films were etched in 6.25 mol/L NaOH solution at 70°C for 12 h,and rinsed with water for 6 *** experiment results show that calibration factor of the SSNTD decreased with increasing humidity,because of increased stopping power of the moisture-absorbed film surface to α***,the calibration factor K should be corrected from the calculated result.

关键词： SSNTD 原子核物理学能级原子核

Arsenic concentration in peripheral blood is correlated with efficacy of a Traditional Chinese Medicine regimen containing realgar for the treatment of myelodysplastic syndromes

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Journal of Traditional Chinese Medicine 2021年第4期41卷 630-635页

作者： WANG Dexiu xu yonggang DU Yu WANG Hongzhi LI Liu HU Xiaomei YANG Xiupeng MA Rou ZHOU Qingbing Department of Hematology Xiyuan HospitalChina Academy of Chinese Medical SciencesBeijing 100091China Institute of Geriatric Medicine Xiyuan HospitalChinese Academy of Chinese Medical SciencesBeijing 100091China

OBJECTIVE:To explore the relationship between the efficacy of realgar for the treatment of myelodysplastic syndromes with multilineage dysplasia(MDS-MLD)and arsenic concentration in the peripheral blood of ***:In this prospective study,a total of 50 MDS-MLD patients were treated with traditional Chinese drugs containing realgar for 3 months in Xiyuan Hospital from March 2018 to January *** blood examination as well as liver and kidney function were monitored before and after *** concentration of arsenic in the peripheral blood was measured using an atomic fluorescence spectrometer after *** correlation between clinical effect and arsenic concentration was analyzed by Spearman’s ***:The treatment response rate was 54%.Two patients(4%)achieved complete remission,50%(25 of 50)showed hematologic improvement,and 23 patients had stable disease(23%).No disease progression was *** concentration in the peripheral blood ranged from 14.60 to 85.96μg/*** efficacy was positively correlated with arsenic concentration(P<0.05).The incidence of mild adverse reactions was 16%.CONCLUSION:A relatively high concentration of arsenic in the peripheral blood may improve the clinical efficacy of realgar in MDS-MLD patients.

关键词： realgar arsenic myelodysplastic syndromes multiline dysplasia

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V元素对Fe-16Cr-2.5Mo合金磁机械阻尼的影响

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材料导报 2021年第14期35卷 14115-14119页

作者：胥晓强胥永刚西南交通大学材料先进技术教育部重点实验室成都610031 江苏科达汽车实业有限公司扬州225800

本实验制备了四种具有不同V含量(0%、0.05%、0.1%和0.2%,质量分数)的Fe-16Cr-2.5Mo阻尼合金。通过光学显微镜观察其微观结构,并通过倒扭摆内耗仪来测试其阻尼性能。通过XRD在施加饱和磁场条件下测量了Fe-16Cr-2.5Mo合金的饱和磁致伸缩系... 详细信息

本实验制备了四种具有不同V含量(0%、0.05%、0.1%和0.2%,质量分数)的Fe-16Cr-2.5Mo阻尼合金。通过光学显微镜观察其微观结构,并通过倒扭摆内耗仪来测试其阻尼性能。通过XRD在施加饱和磁场条件下测量了Fe-16Cr-2.5Mo合金的饱和磁致伸缩系数,并通过振动样品磁强计测量其磁性能。结果表明,V的添加使Fe-16Cr-2.5Mo基合金的晶胞收缩。同时,V造成的固溶强化和细晶强化使合金的强度和韧性逐渐提高。在外磁场的作用下,V元素的添加导致合金出现负磁致伸缩现象,且随着V浓度的升高,合金的磁致伸缩系数绝对值增大、阻尼性能提高。

关键词： Fe-16Cr-2.5Mo合金 V元素阻尼性能磁致伸缩

基于OSF的SET信号重构方法及故障诊断应用

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振动．测试与诊断 2020年第6期40卷 1077-1082,1229页

作者：胥永刚张浩于刚张坤北京工业大学先进制造技术北京市重点实验室北京100124 济南大学自动化与电气工程学院济南250022

同步提取变换(synchroextracting transform,简称SET)通过提取短时傅里叶变换(short-time Fourier transform,简称STFT)在瞬时频率位置的时频系数可获得较理想的时频谱,该方法提高了时频分辨率,减少了交叉项的影响,一定程度上抑制了噪声... 详细信息

同步提取变换(synchroextracting transform,简称SET)通过提取短时傅里叶变换(short-time Fourier transform,简称STFT)在瞬时频率位置的时频系数可获得较理想的时频谱,该方法提高了时频分辨率,减少了交叉项的影响,一定程度上抑制了噪声对STFT时频谱的干扰。针对在SET时频谱的基础上进行信号分量的重构与故障诊断拓展方面的应用,提出了一种基于顺序统计滤波器(order statistics filter,简称OSF)的SET信号分量重构方法。首先,利用边际谱表征SET时频谱中信号的幅值在整个频率范围内随频率变化的情况;其次,采用顺序统计滤波器分割边际谱,将分割所得边界映射至SET时频谱后,利用SET逆变换重构信号分量;最后,利用峭度指标筛选包含丰富故障信息的分量并进行包络分析,提取故障特征。仿真信号及滚动轴承内圈故障信号的处理结果证明了该方法的有效性。

关键词：同步提取变换信号重构顺序统计滤波器滚动轴承故障诊断

基于信源估计和频域反卷积的滚动轴承故障特征分离与辨识

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中国机械工程 2017年第1期28卷 45-51页

作者：张建宇孟浩胥永刚北京工业大学先进制造技术北京市重点实验室北京100124 卧龙电气章丘海尔电机有限公司章丘250200 北京市精密测控技术与仪器工程技术研究中心北京100124

针对轴承故障的振动特征由于受到强振源的抑制作用而增加了故障分离与辨识难度的问题,建立了基于信源估计和频域反卷积的故障诊断方法。利用小波包分解将信号分离成多个子带信号,并和奇异值分解相结合,解决欠定条件下的信号源数估计问题... 详细信息

针对轴承故障的振动特征由于受到强振源的抑制作用而增加了故障分离与辨识难度的问题,建立了基于信源估计和频域反卷积的故障诊断方法。利用小波包分解将信号分离成多个子带信号,并和奇异值分解相结合,解决欠定条件下的信号源数估计问题;根据估计的源数,选取相应维数的观测信号,通过短时傅里叶变换、复数域独立分量分析、相关排序、短时傅里叶逆变换,完成频域反卷积的分析过程,实现故障特征的分离与提取。仿真信号和实验数据均验证了该方法在故障特征分离与微弱特征辨识中的有效性。

关键词：小波包分解奇异值分解短时傅里叶变换复数域独立分量分析频域反卷积

基于BN-1DCNN的旋转机械故障诊断研究

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振动与冲击 2021年第19期40卷 302-308页

作者：冯浩楠付胜胥永刚北京工业大学材料与制造学部北京100124 三亚学院理工学院海南三亚572022

为了对旋转机械的故障特征进行自适应提取,实现智能故障诊断,提出了一种基于批量归一化的一维卷积神经网络(convolutional neural networks,CNN)模型。由于卷积神经网络通常应用于二维图像或三维视频领域,故通过将卷积核改进为一维卷积... 详细信息

为了对旋转机械的故障特征进行自适应提取,实现智能故障诊断,提出了一种基于批量归一化的一维卷积神经网络(convolutional neural networks,CNN)模型。由于卷积神经网络通常应用于二维图像或三维视频领域,故通过将卷积核改进为一维卷积核来实现对采集的一维振动数据的直接卷积,并且采用了批归一化层来防止过拟合,采用HZXT-008小型转子实验台采集的数据对该方法进行验证。试验结果表明该方法平均诊断准确率高达98.43%,并且与其他模型相比稳定性更高。该方法实现了大量样本下旋转机械不同故障类型的故障特征自适应提取与故障类型的准确识别。

关键词：深度学习卷积神经网络(CNN) 旋转机械故障诊断