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Time-domain dynamic constitutive model suitable for mucky soil site seismic response
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作者 Dong Qing Chen Su +2 位作者 Jin Liguo Zhou Zhenghua Li Xiaojun 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第1期1-13,共13页
Soil nonlinear behavior displays noticeable effects on the site seismic response.This study proposes a new functional expression of the skeleton curve to replace the hyperbolic skeleton curve.By integrating shear modu... Soil nonlinear behavior displays noticeable effects on the site seismic response.This study proposes a new functional expression of the skeleton curve to replace the hyperbolic skeleton curve.By integrating shear modulus and combining the dynamic skeleton curve and the damping degradation coefficient,the constitutive equation of the logarithmic dynamic skeleton can be obtained,which considers the damping effect in a soil dynamics problem.Based on the finite difference method and the multi-transmitting boundary condition,a 1D site seismic response analysis program called Soilresp1D has been developed herein and used to analyze the time-domain seismic response in three types of sites.At the same time,this study also provides numerical simulation results based on the hyperbolic constitutive model and the equivalent linear method.The results verify the rationality of the new soil dynamic constitutive model.It can analyze the mucky soil site nonlinear seismic response,reflecting the deformation characteristics and damping effect of the silty soil.The hysteresis loop area is more extensive,and the residual strain is evident. 展开更多
关键词 seismic response time-domain dynamic constitutive model logarithmic dynamic skeleton dampening effect mucky soil
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Complex variable approach in studying modified polarization saturation model in two-dimensional semipermeable piezoelectric media 被引量:1
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作者 S. SINGH K. SHARMA R. R. BHARGAVA 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2017年第11期1517-1532,共16页
A modified polarization saturation model is proposed and addressed math- ematically using a complex variable approach in two-dimensional (2D) semipermeable piezoelectric media. In this model, an existing polarizatio... A modified polarization saturation model is proposed and addressed math- ematically using a complex variable approach in two-dimensional (2D) semipermeable piezoelectric media. In this model, an existing polarization saturation (PS) model in 2D piezoelectric media is modified by considering a linearly varying saturated normal electric displacement load in place of a constant normal electric displacement load, applied on a saturated electric zone. A centre cracked infinite 2D piezoelectric domain subject to an arbitrary poling direction and in-plane electromechanical loadings is considered for the analytical and numerical studies. Here, the problem is mathematically modeled as a non-homogeneous Riemann-Hilbert problem in terms of unknown complex potential functions representing electric displacement and stress components. Having solved the Hilbert problem, the solutions to the saturated zone length, the crack opening displace- ment (COD), the crack opening potential (COP), and the local stress intensity factors (SIFs) are obtained in explicit forms. A numerical study is also presented for the proposed modified model, showing the effects of the saturation condition on the applied electrical loading, the saturation zone length, and the COP. The results of fracture parameters obtained from the proposed model are compared with the existing PS model subject to electrical loading, crack face conditions, and polarization angles. 展开更多
关键词 complex variable fracture parameter local stress intensity factor (SIF) piezoelectric polarization saturation (PS) model
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Modeling Macrophage Polarization and Its Effect on Cancer Treatment Success 被引量:1
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作者 Valentin Morales Luis Soto-Ortiz 《Open Journal of Immunology》 2018年第2期36-80,共45页
Positive feedback loops drive immune cell polarization toward a pro-tumor phenotype that accentuates immunosuppression and tumor angiogenesis. This phenotypic switch leads to the escape of cancer cells from immune des... Positive feedback loops drive immune cell polarization toward a pro-tumor phenotype that accentuates immunosuppression and tumor angiogenesis. This phenotypic switch leads to the escape of cancer cells from immune destruction. These positive feedback loops are generated by cytokines such as TGF-β, Interleukin-10 and Interleukin-4, which are responsible for the polarization of monocytes and M1 macrophages into pro-tumor M2 macrophages, and the polarization of naive helper T cells intopro-tumor Th2 cells. In this article, we present a deterministic ordinary differential equation (ODE) model that includes key cellular interactions and cytokine signaling pathways that lead to immune cell polarization in the tumor microenvironment. The model was used to simulate various cancer treatments in silico. We identified combination therapies that consist of M1 macrophages or Th1 helper cells, coupled with an anti-angiogenic treatment, that are robust with respect to immune response strength, initial tumor size and treatment resistance. We also identified IL-4 and IL-10 as the targets that should be neutralized in order to make these combination treatments robust with respect to immune cell polarization. The model simulations confirmed a hypothesis based on published experimental evidence that a polarization into the M1 and Th1 phenotypes to increase the M1-to-M2 and Th1-to-Th2 ratios plays a significant role in treatment success. Our results highlight the importance of immune cell reprogramming as a viable strategy to eradicate a highly vascularized tumor when the strength of the immune response is characteristically weak and cell polarization to the pro-tumor phenotype has occurred. 展开更多
关键词 MACROPHAGE polarization Feedback LOOPS IMMUNOSUPPRESSION MATHEMATICAL modelING Cancer Therapy
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Ferroelectric effect and equivalent polarization charge model of PbZr_(0.2)Ti_(0.8)O_(3)on AlGaN/GaN MIS-HEMT 被引量:1
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作者 赵垚澎 王冲 +6 位作者 郑雪峰 马晓华 李昂 刘凯 何云龙 陆小力 郝跃 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第5期602-606,共5页
PbZr_(0.2)Ti_(0.8)O_(3)(PZT)gate insulator with the thickness of 30 nm is grown by pulsed laser deposition(PLD)in AlGaN/GaN metal-insulator-semiconductor high electron mobility transistors(MIS-HEMTs).The ferroelectric... PbZr_(0.2)Ti_(0.8)O_(3)(PZT)gate insulator with the thickness of 30 nm is grown by pulsed laser deposition(PLD)in AlGaN/GaN metal-insulator-semiconductor high electron mobility transistors(MIS-HEMTs).The ferroelectric effect of PZT AlGaN/GaN MIS-HEMT is demonstrated.The polarization charge in PZT varies with different gate voltages.The equivalent polarization charge model(EPCM)is proposed for calculating the polarization charge and the concentration of two-dimensional electron gas(2DEG).The threshold voltage(V_(th))and output current density(I_(DS))can also be obtained by the EPCM.The theoretical values are in good agreement with the experimental results and the model can provide a guide for the design of the PZT MIS-HEMT.The polarization charges of PZT can be modulated by different gate-voltage stresses and the V_(th)has a regulation range of 4.0 V.The polarization charge changes after the stress of gate voltage for several seconds.When the gate voltage is stable or changes at high frequency,the output characteristics and the current collapse of the device remain stable. 展开更多
关键词 PZT ALGAN/GAN MIS-HEMT equivalent polarization charge model(EPCM)
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A novel order-reduced thermal-coupling electrochemical model for lithium-ion batteries
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作者 谢奕展 王舒慧 +1 位作者 王震坡 程夕明 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期637-654,共18页
Although the single-particle model enhanced with electrolyte dynamics(SPMe)is simplified from the pseudo-twodimensional(P2D)electrochemical model for lithium-ion batteries,it is difficult to solve the partial differen... Although the single-particle model enhanced with electrolyte dynamics(SPMe)is simplified from the pseudo-twodimensional(P2D)electrochemical model for lithium-ion batteries,it is difficult to solve the partial differential equations of solid–liquid phases in real-time applications.Moreover,working temperatures have a heavy impact on the battery behavior.Hence,a thermal-coupling SPMe is constructed.Herein,a lumped thermal model is established to estimate battery temperatures.The order of the SPMe model is reduced by using both transfer functions and truncation techniques and merged with Arrhenius equations for thermal effects.The polarization voltage drop is then modified through the use of test data because its original model is unreliable theoretically.Finally,the coupling-model parameters are extracted using genetic algorithms.Experimental results demonstrate that the proposed model produces average errors of about 42 mV under 15 constant current conditions and 15 mV under nine dynamic conditions,respectively.This new electrochemicalthermal coupling model is reliable and expected to be used for onboard applications. 展开更多
关键词 lithium-ion batteries order-reduced electrochemical models SPME thermal-coupling model transient polarization voltage drop
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Constant charge method or constant potential method:Which is better for molecular modeling of electrical double layers?
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作者 Liang Zeng Xi Tan +5 位作者 Xiangyu Ji Shiqi Li Jinkai Zhang Jiaxing Peng Sheng Bi Guang Feng 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第7期54-60,共7页
In molecular modeling of electrical double layers(EDLs),the constant charge method(CCM)is prized for its computational efficiency but cannot maintain electrode equipotentiality like the more resourceintensive constant... In molecular modeling of electrical double layers(EDLs),the constant charge method(CCM)is prized for its computational efficiency but cannot maintain electrode equipotentiality like the more resourceintensive constant potential method(CPM),potentially leading to inaccuracies.In certain scenarios,CCM can yield results identical to CPM.However,there are no clear guidelines to determine when CCM is sufficient and when CPM is required.Here,we conduct a series of molecular simulations across various electrodes and electrolytes to present a comprehensive comparison between CCM and CPM under different charging modes.Results reveal that CCM approximates CPM effectively in capturing equilibrium EDL and current-driven dynamics in open electrode systems featuring ionic liquids or regular concentration aqueous electrolytes,while CPM is indispensable in scenarios involving organic and highly concentrated aqueous electrolytes,nanoconfinement effects,and voltage-driven dynamics.This work helps to select appropriate methods for modeling EDL systems,prioritizing accuracy while considering computationalefficiency. 展开更多
关键词 Electrochemical interface Molecular dynamics Electrode polarization modeling Nanoconfinement effect
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A two-dimensional fully analytical model with polarization effect for off-state channel potential and electric field distributions of GaN-based field-plated high electron mobility transistor
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作者 毛维 佘伟波 +11 位作者 杨翠 张超 张进成 马晓华 张金风 刘红侠 杨林安 张凯 赵胜雷 陈永和 郑雪峰 郝跃 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第8期487-494,共8页
In this paper, we present a two-dimensional (2D) fully analytical model with consideration of polarization effect for the channel potential and electric field distributions of the gate field-plated high electron mob... In this paper, we present a two-dimensional (2D) fully analytical model with consideration of polarization effect for the channel potential and electric field distributions of the gate field-plated high electron mobility transistor (FP-HEMT) on the basis of 2D Poisson's solution. The dependences of the channel potential and electric field distributions on drain bias, polarization charge density, FP structure parameters, A1GaN/GaN material parameters, etc. are investigated. A simple and convenient approach to designing high breakdown voltage FP-HEMTs is also proposed. The validity of this model is demonstrated by comparison with the numerical simulations with Silvaco-Atlas. The method in this paper can be extended to the development of other analytical models for different device structures, such as MIS-HEMTs, multiple-FP HETMs, slant-FP HEMTs, etc. 展开更多
关键词 analytical model of GaN-based field-plated HEMT polarization effect POTENTIAL electric field
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A Study on The Multi-Antenna Geometrical Depolarization Channel Modeling 被引量:2
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作者 SUN Xuehong YANG Xiaoli +2 位作者 ZENG Zhimin ZHANG Cheng BAI Bing 《China Communications》 SCIE CSCD 2016年第3期105-114,共10页
The traditional geometrical depolarization model that single transmitter to single receiver provides a simple method of polarization channel modeling. It can obtain the geometrical depolarization effect of each path i... The traditional geometrical depolarization model that single transmitter to single receiver provides a simple method of polarization channel modeling. It can obtain the geometrical depolarization effect of each path if known the antenna configuration, the polarization field radiation pattern and the spatial distribution of scatters. With the development of communication technology, information transmission spectrum is more and more scarce. The original model provides only a single channel polarization state, so the information will be limited that the polarization state carries in the polarization modulation. The research is so significance that how to carries polarization modulation information by using multi-antenna polarization state. However, the present study shows that have no depolarization effect model for multi-antenna systems. In this paper, we propose a multi-antenna geometrical depolarization model. On the basis of a single antenna to calculate the depolarization effect of the model, and through simulation to analysis the main factors that influence the depolarization effect. This article provides a multi-antenna geometrical depolarization channel modeling that can applied to large-scale array antenna, and to some extent increase the speed of information transmission. 展开更多
关键词 去极化作用 多天线系统 信道建模 几何 极化模型 信息传输 偏振状态 建模方法
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Comparative Study on Polarization Spectral Parameters of Fruit in Southern Xinjiang Based on Roujean Model
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作者 Jiayi Xu Xue Huang +2 位作者 Huaping Luo Yuting Suo Feng Gao 《American Journal of Analytical Chemistry》 2021年第3期59-73,共15页
Based on the study of phase angle and wavelength in pBRDF (Polarized bidirectional reflectance distribution function), roujean model was proposed to describe Orient (Polarization phase angle) quantitatively. The Rouje... Based on the study of phase angle and wavelength in pBRDF (Polarized bidirectional reflectance distribution function), roujean model was proposed to describe Orient (Polarization phase angle) quantitatively. The Roujean model was used to quantitatively describe different fruits intensity components (<i><span style="font-family:Verdana;font-size:12px;">F</span></i><sub><span style="font-family:Verdana;font-size:12px;vertical-align:sub;">00</span></sub><span style="font-family:Verdana;font-size:12px;">) and polarization phase angle (Orient), and the simulation results were analyzed and compared using statistical analysis and comparison methods to realize the prediction from the regular model to the outdoor fruit tree canopy to the canopy of outdoor fruit tree canopy random distribution. The experimental results showed that: 1) when the phase angle of jujube was 52.19<span style="white-space:nowrap;">&#176;</span>, 66.51<span style="white-space:nowrap;">&#176;</span></span><span style="font-family:Verdana;font-size:12px;"> </span><span style="font-family:Verdana;font-size:12px;">and 88.26<span style="white-space:nowrap;">&#176;</span>, the </span><i><span style="font-family:Verdana;font-size:12px;">R</span></i><sup><span style="font-family:Verdana;font-size:12px;vertical-align:super;">2</span></sup><span style="font-family:Verdana;font-size:12px;"> and average errors of </span><i><span style="font-family:Verdana;font-size:12px;">F</span></i><sub><span style="font-family:Verdana;font-size:12px;vertical-align:sub;">00</span></sub><span style="font-family:Verdana;font-size:12px;"> parameters described by Roujean model are 0.9982, 0.9963, 0.9912 and 3.80%, 4.17%, 6.40%, respectively;</span><span style="font-family:Verdana;font-size:12px;"> </span><span style="font-family:Verdana;font-size:12px;">a</span><span style="font-family:Verdana;font-size:12px;">nd the </span><i><span style="font-family:Verdana;font-size:12px;">R</span></i><sup><span style="font-family:Verdana;font-size:12px;vertical-align:super;">2</span></sup><span style="font-family:Verdana;font-size:12px;"> and average error of Orient parameters described by Roujean model are 0.9056,</span><span style="font-family:Verdana;font-size:12px;"> </span><span style="font-family:Verdana;font-size:12px;">0.9223,</span><span style="font-family:Verdana;font-size:12px;"> </span><span style="font-family:Verdana;font-size:12px;">0.9260 and 6.23%,</span><span style="font-family:Verdana;font-size:12px;"> </span><span style="font-family:Verdana;font-size:12px;">3.32%,</span><span style="font-family:Verdana;font-size:12px;"> </span><span style="font-family:Verdana;font-size:12px;">8.05%, respectively;It can be seen that roujean model can quantitatively describe the Orient parameter of jujube</span><span style="font-family:Verdana;font-size:12px;">;</span><span style="font-family:Verdana;font-size:12px;">2) When the phase angle of apricot was 70.99<span style="white-space:nowrap;">&#176;</span>, 71.28<span style="white-space:nowrap;">&#176;</span> and 67.91<span style="white-space:nowrap;">&#176;</span>, the </span><i><span style="font-family:Verdana;font-size:12px;">R</span></i><sup><span style="font-family:Verdana;font-size:12px;vertical-align:super;">2</span></sup><span style="font-family:Verdana;font-size:12px;"> and average errors of </span><i><span style="font-family:Verdana;font-size:12px;">F</span></i><sub><span style="font-family:Verdana;font-size:12px;vertical-align:sub;">00</span></sub><span style="font-family:Verdana;font-size:12px;"> parameters described by Roujean model </span><span style="font-family:Verdana;font-size:12px;">is</span><span style="font-family:Verdana;font-size:12px;"> 0.9862, 0.9823, 0.9792 and 3.40%,</span><span style="font-family:Verdana;font-size:12px;"> </span><span style="font-family:Verdana;font-size:12px;">4.82%,</span><span style="font-family:Verdana;font-size:12px;"> </span><span style="font-family:Verdana;font-size:12px;">5.19%, respectively;</span><span style="font-family:Verdana;font-size:12px;"> </span><span style="font-family:Verdana;font-size:12px;">And the R</span><sup><span style="font-family:Verdana;font-size:12px;vertical-align:super;">2</span></sup><span style="font-family:Verdana;font-size:12px;"> and average error of Orient parameters described by Roujean model are 0.9382, 0.8947, 0.8849 and 7.19%, 9.28%, 9.47%, respectively.</span><span style="font-family:Verdana;font-size:12px;"> </span><span style="font-family:Verdana;font-size:12px;">Roujean model can also quantitatively describe the Orient parameter of white apricot. In summary, the Roujean model can provide a good quantitative description of </span><i><span style="font-family:Verdana;font-size:12px;">f</span></i><sub><span style="font-family:Verdana;font-size:12px;vertical-align:sub;">00</span></sub><span style="font-family:Verdana;font-size:12px;"> and a good quantitative description of Orient, which in turn can predict the pBRDF parameter for more fruits with different incidence and detection directions.</span><span style="font-family:Verdana;font-size:12px;"> </span><span style="font-family:Verdana;font-size:12px;">It can correct the influence of angle factor in the nondestructive testing of outdoor fruits.</span> 展开更多
关键词 Bidirectional Reflectivity Distribution Function Degree of Linear polarization Intensity Component Roujean model Phase Angle
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POLARIZATION IMAGING AND SCATTERING MODEL OF CANCEROUS LIVER TISSUES
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作者 DONGZHI LI HONGHUI HE +4 位作者 NAN ZENG E DU RAN LIAO YONGHONG HE HUI MA 《Journal of Innovative Optical Health Sciences》 SCIE EI CAS 2013年第3期91-98,共8页
We apply diferent polarization imaging techniques for cancerous liver tissues,and compare the relative contrasts for difference polarization imaging(DPI),degree of polarization imaging(DOPI)and rotating linear polariz... We apply diferent polarization imaging techniques for cancerous liver tissues,and compare the relative contrasts for difference polarization imaging(DPI),degree of polarization imaging(DOPI)and rotating linear polarization imaging(RLPI).Experimental results show that a number of polarization imaging parameters are capable of differentiating cancerous cells in isotropic liver tisues.To analyze the contrast mechanism of the cancer:-sensitive polarization imaging parameters,we propose a scattering model cont aining two types of spherical scatterers and carry on Monte Carlo simula tions based on this bi-component model.Both the experimental and Monte Carlo simulated results show that the RLPI technique can provide a good imaging contrast of cancerous tissues.The bi-component scattering model provides a useful tool to ana-lyze the contrast mechanism of polarization imaging of cancerous tissues. 展开更多
关键词 polarization imaging liver cancerous tisues sca tering model Monte Carlo si mul ation
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High-Temperature Performance Analysis of AlGaN/GaN Polarization Doped Field Effect Transistors Based on the Quasi-Multi-Channel Model
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作者 房玉龙 冯志红 +6 位作者 李成明 宋旭波 尹甲运 周幸叶 王元刚 吕元杰 蔡树军 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第3期117-120,共4页
We report on the temperature-dependent dc performance of A1GaN/GaN polarization doped field effect transistors (PolFETs). The rough decrements of drain current and transeonductance with the operation temperature are... We report on the temperature-dependent dc performance of A1GaN/GaN polarization doped field effect transistors (PolFETs). The rough decrements of drain current and transeonductance with the operation temperature are observed. Compared with the conventional HFETs, the drain current drop of the PolFET is smaller. The transeonductance drop of PolFETs at different gate biases shows different temperature dependences. From the aspect of the unique carrier behaviors of graded AlGaN/GaN heterostructure, we propose a quasi-multi-channel model to investigate the physics behind the temperature-dependent performance of AlGaN/GaN PolFETs. 展开更多
关键词 AlGaN High-Temperature Performance Analysis of AlGaN/GaN polarization Doped Field Effect Transistors Based on the Quasi-Multi-Channel model
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Modeling and Design of LiNbO_3 Electro-optic Polarization Controller
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作者 ZHUXue-jun ZENGQing-gao 《Semiconductor Photonics and Technology》 CAS 2004年第4期268-270,274,共4页
A theoretical model for describing the operation of an electro-optical polarization controller on LiNbO3 is presented. The model can be used to optimize the device’s structure and parameters to reach a specific polar... A theoretical model for describing the operation of an electro-optical polarization controller on LiNbO3 is presented. The model can be used to optimize the device’s structure and parameters to reach a specific polarization control. Meanwhile, some aspects on the design of an electro-optical polarization controller are described. 展开更多
关键词 偏振传感器 电光偏振 LINBO3 SOP 光学设计
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Steady polarization process modelling of noble metal-electrolyte cermet composite electrode
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作者 罗志安 肖建中 +1 位作者 夏风 杨一凡 《中国有色金属学会会刊:英文版》 EI CSCD 2006年第1期142-147,共6页
Cermet composites containing mixture of noble metal phase and electrolyte phase are the state-of-the-art electrode materials used for electrochemical sensor and solid oxide fuel cell(SOFC). A steady polarization model... Cermet composites containing mixture of noble metal phase and electrolyte phase are the state-of-the-art electrode materials used for electrochemical sensor and solid oxide fuel cell(SOFC). A steady polarization model was developed. The model was based on electronic and ionic transfer process together with the electrochemical reaction regardless of mass transport in the electrode. The modelling results can help to understand the electrochemistry of cermet composite electrode. 展开更多
关键词 贵金属 金属陶瓷 复合电极 模拟 氧化锆 SOFC 燃料电池
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Polarization Projection for 3D Geometry-Based Stochastic Channel Model
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作者 PANG Lihua ZHANG Yang +5 位作者 GONG Fengkui WANG Anyi XIAO Liyuan LIANG Xiao WANG Qiaofeng LI Jiandong 《China Communications》 SCIE CSCD 2015年第10期52-63,共12页
Comprehensive radiation characteristics of polarized antenna are crucial in creating practical channel coefficients for next generation wireless communication system designs.Being currently supported within3 D geometr... Comprehensive radiation characteristics of polarized antenna are crucial in creating practical channel coefficients for next generation wireless communication system designs.Being currently supported within3 D geometry-based stochastic channel models(GSCM),field patterns are technically obtained by chamber measurement(or by its best fitting).However,in some channel related performance analysis scenarios,design insight can be crystallized better by starting the derivations with theoretical co-polarization and cross-polarization components.Specifically,these two components are mathematically linked with field patterns through the proposed polarization projection algorithm.In this manuscript,we focus on revealing the transformation criterion of polarization states between the antenna plane and the propagation plane.In practice,it makes retrieving the field patterns by electromagnetic computation possible.Meanwhile,the impact imposed by distinct antenna orientations is geometrically illustrated and consequently incorporated into the proposed algorithm.This will further facilitate flexible performance evaluation of related radio transmission technologies.Our conclusions are verified by the closed-form expression of the dipole field pattern(via an analytical approach) and by chamber measurement results.Moreover,we find that its 2D degenerative case is aligned with the definitions in 3^(rd) generation partnership project(3GPP)technical report 25.996.The most obvious benefit of the proposed algorithm is to significantly reduce the cost on generating channel coefficients in GSCM simulation. 展开更多
关键词 三维几何模型 信道模型 随机 无线通信系统 交叉极化 投影算法 无线传输技术 天线综合
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Recent Progress in Dual-Polarization Radar Research and Applications in China 被引量:18
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作者 Kun ZHAO Hao HUANG +11 位作者 Mingjun WANG Wen-Chau LEE Gang CHEN Long WEN Jing WEN Guifu ZHANG Ming XUE Zhengwei YANG Liping LIU Chong WU Zhiqun HU Sheng CHEN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2019年第9期961-974,共14页
Dual-polarization(dual-pol)radar can measure additional parameters that provide more microphysical information of precipitation systems than those provided by conventional Doppler radar.The dual-pol parameters have be... Dual-polarization(dual-pol)radar can measure additional parameters that provide more microphysical information of precipitation systems than those provided by conventional Doppler radar.The dual-pol parameters have been successfully utilized to investigate precipitation microphysics and improve radar quantitative precipitation estimation(QPE).The recent progress in dual-pol radar research and applications in China is summarized in four aspects.Firstly,the characteristics of several representative dual-pol radars are reviewed.Various approaches have been developed for radar data quality control,including calibration,attenuation correction,calculation of specific differential phase shift,and identification and removal of non-meteorological echoes.Using dual-pol radar measurements,the microphysical characteristics derived from raindrop size distribution retrieval,hydrometeor classification,and QPE is better understood in China.The limited number of studies in China that have sought to use dual-pol radar data to validate the microphysical parameterization and initialization of numerical models and assimilate dual-pol data into numerical models are summarized.The challenges of applying dual-pol data in numerical models and emerging technologies that may make significant impacts on the field of radar meteorology are discussed. 展开更多
关键词 DUAL-polarization RADAR QUANTITATIVE PRECIPITATION estimation PRECIPITATION MICROPHYSICS DROP size distribution numerical model
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Dual-Polarized RIS-Based STBC Transmission with Polarization Coupling Analysis 被引量:1
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作者 ZHOU Mingyong CHEN Xiangyu +4 位作者 TANG Wankai KE Jun Chen JIN Shi CHENG Qiang CUI Tie Jun 《ZTE Communications》 2022年第1期63-75,共13页
The rapid development of the reconfigurable intelligent surface(RIS)technology has given rise to a new paradigm of wireless trans-mitters.At present,most research works on RIS-based transmitters focus on single-polari... The rapid development of the reconfigurable intelligent surface(RIS)technology has given rise to a new paradigm of wireless trans-mitters.At present,most research works on RIS-based transmitters focus on single-polarized RISs.In this paper,we propose a dual-polarized RIS-based transmitter,which realizes 4-transmit space-time block coding(STBC)transmission by properly partitioning RIS’s unit cells and utilizing the degree of freedom of polarization.The proposed scheme is evaluated through a prototype system that utilizes a fabricated dual-polarized phase-adjustable RIS.In particular,the polarization coupling phenomenon in each unit cell of the employed dual-polarized RIS is modeled and analyzed.The experimental results are in good agreement with the theoretical modeling and analysis results,and an initial re-search effort is made on characterizing the polarization coupling property in the dual-polarized RIS. 展开更多
关键词 reconfigurable intelligent surface space-time coding dual polarization coupling modeling PROTOTYPING
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Statistical Modeling of the High Altitude Platform Dual-Polarized MIMO Propagation Channel 被引量:4
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作者 Mingchuan Yang Shuo Zhang +2 位作者 Xinye Shao Qing Guo Wenyan Tang 《China Communications》 SCIE CSCD 2017年第3期43-54,共12页
In order to investigate the benefit of multiple-input multiple-output(MIMO) technique applying to the high altitude platform(HAP), a 2×2 MIMO statistical model, which can accurately describe the channel between H... In order to investigate the benefit of multiple-input multiple-output(MIMO) technique applying to the high altitude platform(HAP), a 2×2 MIMO statistical model, which can accurately describe the channel between HAP and high-speed train, is presented. And dual polarization diversity is particularly considered. Based on first-order three-state Markov chain, the single-input single-output(SISO) channel, a subset of the MIMO channel is first established. The ray tracing approach applied to the digital relief model(DRM) which covers the railway between Xi'an and Zhengzhou is used to obtain the state probability vector and matrix of the state transition probability. The proposed model considers both Doppler shift and temporal correlation, and the polarization correlation and spatial correlation statistical properties of large-scale fading and smallscale fading are analyzed. Moreover, useful numerical results on the MIMO HAP channel outage capacity are provided based on which, significant capacity gains with respect to the conventional SISO case are illustrated. Such statistical channel model can be applied to the future wireless communication system between HAP and high-speed train. 展开更多
关键词 MIMO信道 统计建模 传输信道 高空平台 双极化 状态转移概率 应用效益 多输入多输出
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Study on the Polarization Effect by Ce Doping in MnSb Alloy
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《Wuhan University Journal of Natural Sciences》 CAS 1996年第2期184-186,共3页
Using discrete variational X. method within the local-density-functional theory and cluster models, the electronic structure and magnetic property or MnSh(Ce) are investigated.It is round that Sb5p state is much pola... Using discrete variational X. method within the local-density-functional theory and cluster models, the electronic structure and magnetic property or MnSh(Ce) are investigated.It is round that Sb5p state is much polarized by Ce doping.The spin moment of Sb changes from -0.06 V,in MnSh to -0.32μb, in MnSh(Ce).The interaction between Mn and doped Ce is small compared with that between Sb and Ce in MnSh(Ce).The influence to the magneto-optical Property of MnSh by the doped Ce is discussed. It is expected that the Sb-5p polarization caused by Ce will make MnSh(Ce)a promising magneto-optical material. 展开更多
关键词 discrete variational method cluster model CE MNSB polarization
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Determination of Polarity Terms of Some Nitrogen-Containing Surfactants and Simulated Hydrophobic Tail Models by Gas Chromatography 被引量:3
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作者 BARAKAT Y IBRAHIM V +1 位作者 MOSTAFA N E SHAKER N O 《色谱》 CAS CSCD 北大核心 2005年第4期347-352,共6页
Some polarity terms of two groups of nitrogen-containing surfactants (six alkanolamides and nine polyoxyethylenated long chain amines) are measured through gas chromatography. The apparent methanol carbon number (CM... Some polarity terms of two groups of nitrogen-containing surfactants (six alkanolamides and nine polyoxyethylenated long chain amines) are measured through gas chromatography. The apparent methanol carbon number (CMeOH) and polarity index (IP) values are determined on the investigated surfactants as stationary phases in packed columns. Similarly, CMeOH and IP values are determined on simulated hydrophobic tail (SHT) models. The obtained results reveal that the introduction of SHT approach permits the distinction between the polarities of different surfactants and their head groups. The measured polarity terms are discussed as related to hydrophile-lipophile balance (HLB) number and the hydrophobic group carbon number (RCN). Some equations relating the measured polarity values and these variable have been developed. 展开更多
关键词 气相色谱法 含氮表面活性剂 疏水尾链模型 极性参数 模拟测定
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A preliminary dayglow model for summer auroral images from Polar/UVI
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作者 WANG Lingmin LUAN Xiaoli 《Advances in Polar Science》 2016年第4期272-279,共8页
In this study, we developed a summer dayglow model using auroral emissions acquired by the ultraviolet imager (UVI) onboard the Polar satellite. In the summer polar region, dayglow varies as a cosine-like function o... In this study, we developed a summer dayglow model using auroral emissions acquired by the ultraviolet imager (UVI) onboard the Polar satellite. In the summer polar region, dayglow varies as a cosine-like function of the solar zenith angle (SZA). The shape of this function can be characterized by its amplitude (Amp) and phase (Phi) factors. We first obtained the hourly Amp and Phi factors in summers from 1996 to 2000, and then investigated the universal time (UT) and solar activity variations of these two shape Factors. It was found that both factors were non-linearly dependent on the solar flux for all years, and the Amp factor showed clear UT variations under both low and high solar flux years. Thus, a dayglow model was constructed to consider the above dependencies. After the dayglow was removed automatically from the original UVI images via our model, the remaining auroral precipitation energy flux was in good agreement with previously reported magnetic local time latitude (MLT-MLAT) patterns. Our model provides a fast way to statistically process summer auroral precipitation of Polar/UVI and its variations. 展开更多
关键词 dayglow in auroral images auroral precipitation dayglow model polar/UVI
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