In the paper, the results of investigations of temperature and frequency dependences of dielectric permeability and dielectric loss of compositions LDPE + xvol%Bi<sub>2</sub>Te<sub>3</sub> are ...In the paper, the results of investigations of temperature and frequency dependences of dielectric permeability and dielectric loss of compositions LDPE + xvol%Bi<sub>2</sub>Te<sub>3</sub> are stated. The investigations were carried out at frequency 10 – 10<sup>5</sup> Hz and temperature 20°C - 150°C intervals, respectively. It was revealed that increase of percentage of the filler Bi<sub>2</sub>Te<sub>3</sub> in the matrix, reduces to increase of dielectric permeability and dielectric loss of composites LDPE + xvol%Bi<sub>2</sub>Te<sub>3</sub> in connection with the change reducing to Maxwell-Wagner’s volume polarization and emergence of comparative strong inner field in semiconductor clusters.展开更多
By virtue of the excellent plasticity and tunable transport properties,Ag_(2)S-based materials demonstrate an intriguing prospect for flexible or hetero-shaped thermoelectric applications.Among them,Ag_(2)S_(1-x)Te_(x...By virtue of the excellent plasticity and tunable transport properties,Ag_(2)S-based materials demonstrate an intriguing prospect for flexible or hetero-shaped thermoelectric applications.Among them,Ag_(2)S_(1-x)Te_(x)exhibits rich and interesting variations in crystal structure,mechanical and thermoelectric transport properties.However,Te alloying obviously introduces extremely large order-disorder distributions of cations and anions,leading to quite complicated crystal structures and thermoelectric properties.Detailed composition-structure-performance correlation of Ag_(2)S_(1-x)Te_(x)still remains to be established.In this work,we designed and prepared a series of Ag_(2)S_(1-x)Te_(x)(x=0-0.3)materials with low Te content.We discovered that the monoclinic-to-cubic phase transition occurs around x=0.16 at room temperature.Te alloying plays a similar role as heating in facilitating this monoclinic-to-cubic phase transition,which is analyzed based on the thermodynamic principles.Compared with the monoclinic counterparts,the cubic-structured phases are more ductile and softer in mechanical properties.In addition,the cubic phases show a degenerately semiconducting behavior with higher thermoelectric performance.A maximum zT=0.8 at 600 K and bending strain larger than 20% at room temperature were obtained in Ag_(2)S_(0.7)Te_(0.3).This work provides a useful guidance for designing Ag_(2)S-based alloys with enhanced plasticity and high thermoelectric performance.展开更多
Phase diagrams of the RE （rare earth）-Ⅳ-Ⅵ systems are very important for the design of rare earth doped diluted magnetic semiconductors （DMSs）, but related information is very limited. In this work, the phase eq...Phase diagrams of the RE （rare earth）-Ⅳ-Ⅵ systems are very important for the design of rare earth doped diluted magnetic semiconductors （DMSs）, but related information is very limited. In this work, the phase equilibria of the Er-Sn-Te system in whole compositional range at room temperature were investigated mainly by means of X-ray powder diffraction （XRD） and differential thermal analysis （DTA）. The existences of 9 binary compounds, i.e., SnTe, ErTe3, EraTe3, ErTe, ErsSn3, Er11Sn10, ErSn2, Er3Sn7 and Er2Sn5 were confirmed. The phase diagram consisted of 12 single-phase regions, 21 binary phase regions and 10 ternary phase re- gions. The maximum solid solubility of Er in SnTe was determined to be about 7.5 at.%, none of the other phases in this system re- vealed a remarkable homogeneity range at room temperature. No ternary compound was found in this work.展开更多
针对主元分析(principal component analysis,PCA)中潜隐变量自相关性对故障检测的影响,提出一种基于潜隐变量自相关性子空间划分的故障检测策略(fault detection strategy based on dividing autocorrelation of latent variables,FDD...针对主元分析(principal component analysis,PCA)中潜隐变量自相关性对故障检测的影响,提出一种基于潜隐变量自相关性子空间划分的故障检测策略(fault detection strategy based on dividing autocorrelation of latent variables,FDDA).首先,应用PCA将输入空间通过线性变换分解为主元子空间(principal component subspace,PCS)和残差子空间(residual subspace,RS).其次,依据潜隐变量自相关性的强弱,将上述两个子空间分别进行二次划分.综上,原始输入空间依据方差和自相关性信息被划分成4个子空间,并利用不同的监控指标进行故障检测.子空间划分方法既可以提取输入变量间的相关性,又可以捕获潜隐变量自相关性.通过4个子空间的联合监控,可以有效地解决动态过程的故障检测问题,具有较高的故障检测率.将FDDA方法应用在TE过程和半导体蚀刻过程,并与PCA、动态PCA(dynamic PCA,DPCA)、kNN等进行对比分析,仿真实验结果验证了FDDA方法的有效性.展开更多
文摘In the paper, the results of investigations of temperature and frequency dependences of dielectric permeability and dielectric loss of compositions LDPE + xvol%Bi<sub>2</sub>Te<sub>3</sub> are stated. The investigations were carried out at frequency 10 – 10<sup>5</sup> Hz and temperature 20°C - 150°C intervals, respectively. It was revealed that increase of percentage of the filler Bi<sub>2</sub>Te<sub>3</sub> in the matrix, reduces to increase of dielectric permeability and dielectric loss of composites LDPE + xvol%Bi<sub>2</sub>Te<sub>3</sub> in connection with the change reducing to Maxwell-Wagner’s volume polarization and emergence of comparative strong inner field in semiconductor clusters.
基金This work is supported by the National Key Research and Development Program of China(2018YFB0703600)National Natural Science Foundation of China(91963208,51625205,51961135106,51802333)+2 种基金the CAS-DOE Program of Chinese Academy of Sciences(121631KYSB20180060)the Shanghai Government(20JC1415100)the Swedish Research Council(VR 2018e06030).
文摘By virtue of the excellent plasticity and tunable transport properties,Ag_(2)S-based materials demonstrate an intriguing prospect for flexible or hetero-shaped thermoelectric applications.Among them,Ag_(2)S_(1-x)Te_(x)exhibits rich and interesting variations in crystal structure,mechanical and thermoelectric transport properties.However,Te alloying obviously introduces extremely large order-disorder distributions of cations and anions,leading to quite complicated crystal structures and thermoelectric properties.Detailed composition-structure-performance correlation of Ag_(2)S_(1-x)Te_(x)still remains to be established.In this work,we designed and prepared a series of Ag_(2)S_(1-x)Te_(x)(x=0-0.3)materials with low Te content.We discovered that the monoclinic-to-cubic phase transition occurs around x=0.16 at room temperature.Te alloying plays a similar role as heating in facilitating this monoclinic-to-cubic phase transition,which is analyzed based on the thermodynamic principles.Compared with the monoclinic counterparts,the cubic-structured phases are more ductile and softer in mechanical properties.In addition,the cubic phases show a degenerately semiconducting behavior with higher thermoelectric performance.A maximum zT=0.8 at 600 K and bending strain larger than 20% at room temperature were obtained in Ag_(2)S_(0.7)Te_(0.3).This work provides a useful guidance for designing Ag_(2)S-based alloys with enhanced plasticity and high thermoelectric performance.
基金supported by the Guangxi Science and Technology Development Project (11107003-1)National Natural Science Foundation of China (50601006, 51161002)
文摘Phase diagrams of the RE （rare earth）-Ⅳ-Ⅵ systems are very important for the design of rare earth doped diluted magnetic semiconductors （DMSs）, but related information is very limited. In this work, the phase equilibria of the Er-Sn-Te system in whole compositional range at room temperature were investigated mainly by means of X-ray powder diffraction （XRD） and differential thermal analysis （DTA）. The existences of 9 binary compounds, i.e., SnTe, ErTe3, EraTe3, ErTe, ErsSn3, Er11Sn10, ErSn2, Er3Sn7 and Er2Sn5 were confirmed. The phase diagram consisted of 12 single-phase regions, 21 binary phase regions and 10 ternary phase re- gions. The maximum solid solubility of Er in SnTe was determined to be about 7.5 at.%, none of the other phases in this system re- vealed a remarkable homogeneity range at room temperature. No ternary compound was found in this work.
