期刊文献+
共找到1,728篇文章
< 1 2 87 >
每页显示 20 50 100
轨道参数对钢轨Pinned-Pinned振动的影响 被引量:4
1
作者 张攀 王安斌 +2 位作者 王志强 徐宁 张喆玉 《城市轨道交通研究》 北大核心 2016年第12期72-76,82,共6页
有研究认为钢轨不连续支撑造成的轮轨柔度差变是钢轨波浪磨耗产生和发展的主要原因之一。在此基础上对轨道参数对钢轨Pinned-Pinned振动的影响进行进一步分析。通过利用ANSYS软件建立轨道结构的有限元分析模型,计算分析了不连续支撑条... 有研究认为钢轨不连续支撑造成的轮轨柔度差变是钢轨波浪磨耗产生和发展的主要原因之一。在此基础上对轨道参数对钢轨Pinned-Pinned振动的影响进行进一步分析。通过利用ANSYS软件建立轨道结构的有限元分析模型,计算分析了不连续支撑条件下轨道的支撑刚度、支撑间距和结构阻尼对钢轨柔度特性的影响,并提出了控制钢轨波磨形成与发展的建议。 展开更多
关键词 轨道 pinnedpinned振动 支撑间距 支撑刚度 阻尼
在线阅读 下载PDF
Shaking table test and numerical analysis of a 1:12 scale model of a special concentrically braced steel frame with pinned connections 被引量:7
2
作者 Yu Haifeng Zhang Wenyuan +1 位作者 Zhang Yaochun Sun Yusong 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2010年第1期51-63,共13页
This paper describes shaking table tests of a 1:12 scale model of a special concentrically braced steel frame with pinned connections, which was fabricated according to a one-bay braced frame selected from a typical ... This paper describes shaking table tests of a 1:12 scale model of a special concentrically braced steel frame with pinned connections, which was fabricated according to a one-bay braced frame selected from a typical main factory building of a large thermal power plant. In order to investigate the seismic performance of this type of structure, several ground motion accelerations with different levels for seismic intensity Ⅷ, based on the Chinese Code for Seismic Design of Buildings, were selected to excite the model. The results show that the design methods of the members and the connections are adequate and that the structural system will perform well in regions of high seismicity. In addition to the tests, numerical simulations were also conducted and the results showed good agreement with the test results. Thus, the numerical model is shown to be accurate and the beam element can be used to model this structural system. 展开更多
关键词 concentrically braced steel frame pinned connections shaking table test numerical analysis seismic performance
在线阅读 下载PDF
A dynamic photoresponse model for a pinned photodiode in CMOS image sensors 被引量:1
3
作者 AO Jinghua GAO Zhiyuan +1 位作者 GAO Jing XU Jiangtao 《Optoelectronics Letters》 EI 2022年第7期419-424,共6页
A novel dynamic photoresponse model for complementary metal-oxide-semiconductor(CMOS)image sensors with pinned photodiode(PPD)structures is proposed.The PPD is regarded as the bonding structure of the two p-n junction... A novel dynamic photoresponse model for complementary metal-oxide-semiconductor(CMOS)image sensors with pinned photodiode(PPD)structures is proposed.The PPD is regarded as the bonding structure of the two p-n junctions.The transient current equation of the two junctions is calculated by the current-voltage formula of the p-n junction,and the photoresponse curve of the PPD is calculated and drawn by the numerical solution.Simulation results show that the dynamic model successfully restores the entire process of the electron accumulation in the PPD.The difference between the full well capacity(FWC)values which were calculated by the proposed model and the simulation results is less than 5%,which is much smaller than the error of 40%for the traditional model. 展开更多
关键词 PHOTORESPONSE pinned DYNAMIC
原文传递
A quantum efficiency analytical model for complementary metal–oxide–semiconductor image pixels with a pinned photodiode structure
4
作者 曹琛 张冰 +2 位作者 吴龙胜 李娜 王俊峰 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第12期254-262,共9页
A quantum efficiency analytical model for complementary metal–oxide–semiconductor(CMOS) image pixels with a pinned photodiode structure is developed. The proposed model takes account of the non-uniform doping dist... A quantum efficiency analytical model for complementary metal–oxide–semiconductor(CMOS) image pixels with a pinned photodiode structure is developed. The proposed model takes account of the non-uniform doping distribution in the N-type region due to the impurity compensation formed by the actual fabricating process. The characteristics of two boundary PN junctions located in the N-type region for the particular spectral response of a pinned photodiode, are quantitatively analyzed. By solving the minority carrier steady-state diffusion equations and the barrier region photocurrent density equations successively, the analytical relationship between the quantum efficiency and the corresponding parameters such as incident wavelength, N-type width, peak doping concentration, and impurity density gradient of the N-type region is established. The validity of the model is verified by the measurement results with a test chip of 160×160 pixels array,which provides the accurate process with a theoretical guidance for quantum efficiency design in pinned photodiode pixels. 展开更多
关键词 CMOS image sensor quantum efficiency pinned photodiode analytical model
原文传递
A low-power high-quality CMOS image sensor using 1.5 V 4T pinned photodiode and dual-CDS column-parallel single-slope ADC
5
作者 Wenjing Xu Jie Chen +3 位作者 Zhangqu Kuang Li Zhou Ming Chen Chengbin Zhang 《Journal of Semiconductors》 EI CAS CSCD 2022年第8期53-59,共7页
This paper presents a low-power high-quality CMOS image sensor(CIS)using 1.5 V 4T pinned photodiode(4T-PPD)and dual correlated double sampling(dual-CDS)column-parallel single-slope ADC.A five-finger shaped pixel layer... This paper presents a low-power high-quality CMOS image sensor(CIS)using 1.5 V 4T pinned photodiode(4T-PPD)and dual correlated double sampling(dual-CDS)column-parallel single-slope ADC.A five-finger shaped pixel layer is proposed to solve image lag caused by low-voltage 4T-PPD.Dual-CDS is used to reduce random noise and the nonuniformity between columns.Dual-mode counting method is proposed to improve circuit robustness.A prototype sensor was fabricated using a 0.11μm CMOS process.Measurement results show that the lag of the five-finger shaped pixel is reduced by 80%compared with the conventional rectangular pixel,the chip power consumption is only 36 mW,the dynamic range is 67.3 dB,the random noise is only 1.55 e^(-)_(rms),and the figure-of-merit is only 1.98 e^(-)·nJ,thus realizing low-power and high-quality imaging. 展开更多
关键词 CMOS image sensor 4T pinned photodiode single-slope ADC correlated double sample counting method
在线阅读 下载PDF
A review of recent theoretical and computational studies on pinned surface nanobubbles 被引量:1
6
作者 刘亚伟 张现仁 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第1期136-144,共9页
The observations of long-lived surface nanobubbles in various experiments have presented a theoretical challenge, as they were supposed to be dissolved in microseconds owing to the high Laplace pressure. However, an i... The observations of long-lived surface nanobubbles in various experiments have presented a theoretical challenge, as they were supposed to be dissolved in microseconds owing to the high Laplace pressure. However, an increasing number of studies suggest that contact line pinning, together with certain levels of oversaturation, is responsible for the anomalous stability of surface nanobubbles. This mechanism can interpret most characteristics of surface nanobubbles. Here, we summarize recent theoretical and computational work to explain how the surface nanobubbles become stable with contact line pinning. Other related work devoted to understanding the unusual behaviors of pinned surface nanobubbles is also reviewed here. 展开更多
关键词 surface nanobubble contact line pinning oversaturation lattice density functional theory
原文传递
Investigation of magnetization reversal process in pinned CoFeB thin film by in-situ Lorentz TEM 被引量:1
7
作者 Ke Pei Wei-Xing Xia +5 位作者 Bao-Min Wang Xing-Cheng Wen Ping Sheng Jia-Ping Liu Xin-Cai Liu Run-Wei Li 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第4期465-471,共7页
Exchange bias effect has been widely employed for various magnetic devices.The experimentally reported magnitude of exchange bias field is often smaller than that predicted theoretically,which is considered to be due ... Exchange bias effect has been widely employed for various magnetic devices.The experimentally reported magnitude of exchange bias field is often smaller than that predicted theoretically,which is considered to be due to the partly pinned spins of ferromagnetic layer by antiferromagnetic layer.However,mapping the distribution of pinned spins is challenging.In this work,we directly image the reverse domain nucleation and domain wall movement process in the exchange biased Co Fe B/Ir Mn bilayers by Lorentz transmission electron microscopy.From the in-situ experiments,we obtain the distribution mapping of the pinning strength,showing that only 1/6 of the ferromagnetic layer at the interface is strongly pinned by the antiferromagnetic layer.Our results prove the existence of an inhomogeneous pinning effect in exchange bias systems. 展开更多
关键词 exchange bias magnetization reversal process Lorentz transmission electron microscopy pinning effect distribution
原文传递
P型掺杂区工艺对Si基Pinned型光电二极管量子效率的影响 被引量:1
8
作者 曹琛 张冰 +1 位作者 王俊峰 吴龙胜 《光电子.激光》 EI CAS CSCD 北大核心 2015年第1期54-62,共9页
为了更全面、系统地分析Si基Pinned型光电二极管(PPD,pinned photodiode)量子效率的工艺敏感特性,基于考虑表面(SRH,shockley-read-hall)复合率模型的时域有限差分数值模拟方法,对不同P+型表面层和P型外延(EPI,epitaxial)层工艺... 为了更全面、系统地分析Si基Pinned型光电二极管(PPD,pinned photodiode)量子效率的工艺敏感特性,基于考虑表面(SRH,shockley-read-hall)复合率模型的时域有限差分数值模拟方法,对不同P+型表面层和P型外延(EPI,epitaxial)层工艺条件下PPD可见光谱量子效率的变化特征及物理机制进行了研究。结果表明,P+型表面层离子束注入剂量和注入能量的增加分别引起非平衡载流子SRH复合率升高和PPD势垒区顶部下移,均可导致低于500nm波段量子效率的衰减,而后者进一步引起的势垒区纵向宽度缩减使该影响可持续至650nm波段;P型EPI掺杂浓度增加引起PPD势垒区底部上移,导致500~750nm波段量子效率的衰减;P型EPI厚度增加引起衬底强SRH复合区光电荷比重降低,导致高于700nm波段量子效率得到提升并趋向饱和。通过分析发现,Si基材料中光子吸收深度对波长的强依赖关系是导致两种P型掺杂区工艺条件对量子效率存在波段差异性影响的根本原因。 展开更多
关键词 pinned型光电二极管(PPD) 量子效率 工艺条件 数值模拟
原文传递
Pinch-off voltage modeling for CMOS image pixels with a pinned photodiode structure 被引量:1
9
作者 曹琛 张冰 +2 位作者 吴龙胜 李炘 王俊峰 《Journal of Semiconductors》 EI CAS CSCD 2014年第7期90-96,共7页
A novel analytical model of pinch-off voltage for CMOS image pixels with a pinned photodiode structure is proposed. The derived model takes account of the gradient doping distributions in the N buried layer due to the... A novel analytical model of pinch-off voltage for CMOS image pixels with a pinned photodiode structure is proposed. The derived model takes account of the gradient doping distributions in the N buried layer due to the impurity compensation formed by manufacturing processes; the impurity distribution characteristics of two boundary PN junctions located in the region for particular spectrum response of a pinned photodiode are quantitative analyzed. By solving Poisson's equation in vertical barrier regions, the relationships between the pinch-off voltage and the corresponding process parameters such as peak doping concentration, N type width and doping concentration gradient of the N buried layer are established. Test results have shown that the derived model features the variations of the pinch-off voltage versus the process implant conditions more accurately than the traditional model. The research conclusions in this paper provide theoretical evidence for evaluating the pinch-off voltage design. 展开更多
关键词 pinned photodiode pixel design pinch-off voltage analytical model
原文传递
Measurement of charge transfer potential barrier in pinned photodiode CMOS image sensors 被引量:1
10
作者 曹琛 张冰 +1 位作者 王俊峰 吴龙胜 《Journal of Semiconductors》 EI CAS CSCD 2016年第5期56-60,共5页
The charge transfer potential barrier (CTPB) formed beneath the transfer gate causes a noticeable image lag issue in pinned photodiode (PPD) CMOS image sensors (CIS), and is difficult to measure straightforwardl... The charge transfer potential barrier (CTPB) formed beneath the transfer gate causes a noticeable image lag issue in pinned photodiode (PPD) CMOS image sensors (CIS), and is difficult to measure straightforwardly since it is embedded inside the device. From an understanding of the CTPB formation mechanism, we report on an alternative method to feasibly measure the CTPB height by performing a linear extrapolation coupled with a horizontal left-shift on the sensor photoresponse curve under the steady-state illumination. The theoretical study was pertbrmed in detail on the principle of the proposed method. Application of the measurements oil a prototype PPD-CIS chip with an array of 160 ×160 pixels is demonstrated. Such a method intends to shine new light oil the guidance for the lag-free and high-speed sensors optimization based on PPD devices. 展开更多
关键词 CMOS image sensors (C1S) pinned photodiode (PPD) charge transfer potential barrier (CTPB) photoresponse curve
原文传递
一种平衡式准有源限幅开关一体化接收电路设计
11
作者 王超杰 李志友 +2 位作者 来晋明 王海龙 肖峰 《固体电子学研究与进展》 2026年第1期89-94,共6页
提出了一种平衡式准有源限幅开关一体化接收电路,其核心部件为宽带90°电桥、限幅PIN二极管、检波控制电路以及低噪声放大器。该电路利用输入端电桥隔离端口作为射频输入信号检波电路的提取端,将检波电路输出电平与控制电路相结合,... 提出了一种平衡式准有源限幅开关一体化接收电路,其核心部件为宽带90°电桥、限幅PIN二极管、检波控制电路以及低噪声放大器。该电路利用输入端电桥隔离端口作为射频输入信号检波电路的提取端,将检波电路输出电平与控制电路相结合,使限幅PIN二极管在高功率、高重频脉冲信号输入时处于有源导通状态。因此,限幅PIN二极管可以免受高功率微波脉冲信号的微波阻抗调制,从而提高了电路的耐功率容量和应对复杂输入信号的能力。另外利用3 dB电桥端口间的隔离特性,电路在任意负载态时均具有良好输入输出驻波。在2~6 GHz频段范围内,所提出电路耐受脉冲或连续波功率为100 W,噪声系数优于1.7 dB,增益大于23 dB,尺寸为8 mm×5 mm×1 mm。 展开更多
关键词 吸收式限幅器 PIN二极管 3 dB电桥 平衡式限幅低噪放
原文传递
A PINNED NETWORK OF EULER-BERNOULLI BEAMS UNDER FEEDBACK CONTROLS
12
作者 ZHANG Kuiting XU Genqi 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2013年第3期313-334,共22页
In this paper, the authors design boundary feedback controllers at the interior node to stabilize a star-shaped network of Euler-Bernoulli beams. The beams are pinned each other, that is, the displacements of the stru... In this paper, the authors design boundary feedback controllers at the interior node to stabilize a star-shaped network of Euler-Bernoulli beams. The beams are pinned each other, that is, the displacements of the structure are continuous but the rotations of the beams are not continuous. The weil-posed-ness of the closed loop system is proved by the semigroup theory. The authors show that the system is asymptotically stable if the authors impose a bending moment control on each edge. Finally, the authors derive the exponential stability of the system. 展开更多
关键词 Euler-Bernoulli beams pinned network semigroup theory stability.
原文传递
Photoelectric characteristics of an inverse U-shape buried doping design for crosstalk suppression in pinned photodiodes
13
作者 曹琛 张冰 +2 位作者 李炘 吴龙胜 王俊峰 《Journal of Semiconductors》 EI CAS CSCD 2014年第11期81-89,共9页
A design of an inverse U-shape buried doping in a pinned photodiode (PPD) of CMOS image sensors is proposed for electrical crosstalk suppression between adjacent pixels. The architecture achieves no extra fill facto... A design of an inverse U-shape buried doping in a pinned photodiode (PPD) of CMOS image sensors is proposed for electrical crosstalk suppression between adjacent pixels. The architecture achieves no extra fill factor consumption, and proper built-in electric fields can be established according to the doping gradient created by the injections of the extremely low P-type doping buried regions in the epitaxial layer, causing the excess electrons to easily drift back to the photosensitive area rarely with a diffusion probability; the overall junction capacitance and photosensitive area extensions for a full well capacity (FWC) and internal quantum efficiency (IQE) improving are achieved by the injection of a buried N-type doping. By considering the image lag issue, the process parameters of all the injections have been precisely optimized. Optical simulation results based on the finite difference time domain method show that compared to the conventional PPD, the electrical crosstalk rate of the proposed architecture can be decreased by 60%-80% at an incident wavelength beyond 450 nm, IQE can be clearly improved at an incident wavelength between 400 and 600 nm, and the FWC can be enhanced by 107.5%. Furthermore, the image lag performance is sustained to a perfect low level. The present study provides important guidance on the design of ultra high resolution image sensors. 展开更多
关键词 CMOS image sensor electrical crosstalk photoelectric performance design pinned photodiode
原文传递
400/800V数据中心交直流高压电源连接器的研发
14
作者 杨艳辉 胡盛 谭锦涛 《机电元件》 2026年第1期3-7,共5页
本文介绍高压交直流系统中具有灭弧功效的电源连接器。该结构是利用电磁铁及导弧角对电弧进行拉长,接触区与热插拔时起弧区分离加快电弧的熄灭,保证接触件在多次热插拔后仍能有效。同时,该连接器具有多类别的信号PIN针高压互锁功能。
关键词 电磁铁 导弧角 灭弧 电弧 互锁 PIN针
在线阅读 下载PDF
Suppressing planar gliding and cation migration in O3-type layered oxide cathode for long-life and wide-temperature sodium-ion batteries
15
作者 Peng Yu Nini Liu +10 位作者 Yizhong Gou Daomin Qin Wen Zhang Lihua Feng Yameng Fan Yu Wang Changhong Wang Jiantao Han Yunhui Huang Jian Peng Chun Fang 《Journal of Energy Chemistry》 2026年第2期789-799,I0017,共12页
Sodium layered oxides stand out as one of the most promising cathodes for sodium-ion batteries due to their high energy density,elemental abundance,and scalability.However,their practical applications are restricted b... Sodium layered oxides stand out as one of the most promising cathodes for sodium-ion batteries due to their high energy density,elemental abundance,and scalability.However,their practical applications are restricted by interplanar gliding,cation migration,and the formation of intragranular microcracks,which collectively lead to rapid structural degradation and capacity loss.Herein,we rationally design an ultrastable O3-type Na_(0.94)Ca_(0.03)Ni_(1/3)Fe_(1/3)Mn_(1/3)O_(2) cathode,in which Ca^(2+)cations act as pillars within the NaO_(2)slabs,suppressing the irreversible phase transitions and Na/TM cation migration commonly observed in layered oxides.Multiscale in situ and ex situ techniques,combined with post-mortem analysis,reveal that the Ca-pillared pinning effect not only effectively suppresses the interplanar gliding and stress accumulation within the crystal phase but also restrains Na/TM cation migration and surface reconstruction in near-surface regions.Benefiting from the combined effects of structural stabilization,the Ca-pillared cathode exhibits a superior cycling stability,retaining 81.6%of its capacity after 1000 cycles at 2 C within the voltage range of 2.0-4.0 V,along with significantly enhanced wide-temperature(from-40 to 80℃)performance.This work highlights another critical role of Ca pillars in suppressing cation migration and surface structural degradation beyond preventing adverse interplanar gliding,offering valuable insights for designing long-life and wide-temperature layered oxide cathodes. 展开更多
关键词 Layered oxide cathodes Pinning effect Planar gliding Cation migration Sodium-ion batteries
在线阅读 下载PDF
TMK1 phosphorylates and stabilizes PIN2 to reinforce auxin flux during root gravitropism
16
作者 Yuanyuan Li Pengyue Zhao 《Advanced Agrochem》 2026年第1期10-12,共3页
Plant growth depends on tightly coordinated auxin signaling and directional auxin transport,yet the molecular feedback mechanism that directly links these processes during root gravitropism has remained mechanisticall... Plant growth depends on tightly coordinated auxin signaling and directional auxin transport,yet the molecular feedback mechanism that directly links these processes during root gravitropism has remained mechanistically unresolved.The recent study by Rodriguez et al.(Cell,2025)reveals a novel cell-surface auxin signaling pathway.It is shown that gravity perception-induced initial auxin asymmetry activates transmembrane kinase 1(TMK1)in the lower side cells of the root.The activated TMK1 then interacts with pin-formed 2(PIN2)and phosphorylates its hydrophilic loop,thereby stabilizing the PIN2 protein.This asymmetric distribution of PIN2 further enhances the auxin flow on the lower side,thus forming a self-reinforcing positive feedback loop that drives force for root tip gravitropic bending.This study provides an updated perspective on the auxin signal and transport feedback,signifying a new advancement in our comprehension of the mechanisms underlying plant adaptive growth. 展开更多
关键词 Auxin signaling TMK1 receptor kinase PIN2 phosphorylation Root gravitropism Positive feedback loop
在线阅读 下载PDF
Z-pinned复合材料层板Ⅰ型裂纹的疲劳扩展
17
作者 张阿盈 《结构强度研究》 2006年第3期30-37,共8页
用数值模拟方法研究z-pin增强复合材料DCB层压板Ⅰ型裂纹的疲劳扩展问题。在理论模型中,将z-pin简化为一系列施加在DCB层板上的外力,这些力在裂纹扩展中对裂纹提供桥接力。基于试验观察,桥接力随疲劳载荷的衰减规律可假设为一个分一... 用数值模拟方法研究z-pin增强复合材料DCB层压板Ⅰ型裂纹的疲劳扩展问题。在理论模型中,将z-pin简化为一系列施加在DCB层板上的外力,这些力在裂纹扩展中对裂纹提供桥接力。基于试验观察,桥接力随疲劳载荷的衰减规律可假设为一个分一。段的幂函数。用一个指数函数表示复合材料DCB层板疲劳断裂韧性与疲劳循环次数的关系,并将此作为裂纹扩展的判据。分析结果表明,无论是位移控制模式还是载荷控制模式,z—pin可以有效地降低分层扩展速率。还就z—pin密度,z-pin大小等参数进行了分析研究。 展开更多
关键词 z-pin增强DCB:z—pin桥接力 Ⅰ型裂纹 疲劳 裂纹扩展速率
原文传递
Electron Movements Pinned down to the Split Second
18
作者 Mark Peplow 全勇 《当代外语研究》 2004年第11期24-22,共2页
1999年的诺贝尔化学奖颁发给了科学家艾哈迈德·译韦尔,以表彰他应用飞秒激光闪光成相技术观测到分子中的原子在化学反应中如何运动,从而为化学及相关科学带来了一场革命。随着飞秒化学领域研究的不断深入,它必将会进一步为科学发... 1999年的诺贝尔化学奖颁发给了科学家艾哈迈德·译韦尔,以表彰他应用飞秒激光闪光成相技术观测到分子中的原子在化学反应中如何运动,从而为化学及相关科学带来了一场革命。随着飞秒化学领域研究的不断深入,它必将会进一步为科学发展做出自己独特的贡献。 展开更多
关键词 Electron Movements pinned down to the Split Second
原文传递
Evaluation of temperature dependent vortex pinning properties in strongly pinned YBa_(2)Cu_(3)O_(7-δ)thin films with Y_(2)BaCuO_(5)nanoinclusions 被引量:1
19
作者 Alok K.Jha Kaname Matsumoto +5 位作者 Tomoya Horide Shrikant Saini Ataru Ichinose Paolo Mele Yutaka Yoshida Satoshi Awaji 《Superconductivity》 2024年第1期95-105,共11页
The pinning of quantized magnetic vortices in superconducting YBa_(2)Cu_(3)O_(7-δ)(YBCO or Y123)thin films with Y_(2)BaCuO_(5)(Y211)nanoinclusions have been investigated over wide temperature range(4.2-77 K).The conc... The pinning of quantized magnetic vortices in superconducting YBa_(2)Cu_(3)O_(7-δ)(YBCO or Y123)thin films with Y_(2)BaCuO_(5)(Y211)nanoinclusions have been investigated over wide temperature range(4.2-77 K).The concentration of Y211 nanoinclusions has been systematically varied inside YBCO thin films prepared by laser ablation technique using surface modified target approach.Large pinning force density values(Fp∼0.5 TNm^(−3)at 4.2 K,9 T)have been observed for the YBCO film with moderate concentration of Y211 nanoinclusions(3.6 area%on ablation target).In addition,uniform enhancement in critical current density(J_(c))was observed in the angular dependent J_(c)measurement of YBCO+Y211 nanocomposite films.Y211 nanoinclusions have been found to be very efficient in pinning the quantized vortices thereby enhancing the in‐field J_(c)values over a wide range of temperature.Increasing the concentration of Y211 secondary phase into Y123 film matrix results into agglomeration of Y211 phase and observed as increased Y211 nanoparticle size.These larger secondary phase nanoparticles are not as efficient pinning centers at lower temperatures as they are at higher temperatures due to substantial reduction of the coherence length at lower temperatures.Investigation of the temperature dependence of J_(c)for YBCO+Y211 nanocomposite films has been conducted and possible vortex pinning mechanism in these nanocomposite films has been discussed. 展开更多
关键词 YBCO thin film Critical current Vortex pinning Nanoscale APCs
原文传递
大频率比的毫米波频率可重构滤波天线 被引量:1
20
作者 杨国 施鸿强 +3 位作者 黎小聪 肖如奇 齐世山 吴文 《物理学报》 北大核心 2025年第1期270-280,共11页
针对现有毫米波频率可重构天线频率调谐比小的问题,本文设计了一款宽频带双频毫米波频率可重构滤波天线.天线以PIN二极管为重构开关,选择阶梯阻抗谐振器作为可重构带通滤波器,并加载U型枝节引入陷波;通过微带线-带状线过渡馈电结构将滤... 针对现有毫米波频率可重构天线频率调谐比小的问题,本文设计了一款宽频带双频毫米波频率可重构滤波天线.天线以PIN二极管为重构开关,选择阶梯阻抗谐振器作为可重构带通滤波器,并加载U型枝节引入陷波;通过微带线-带状线过渡馈电结构将滤波器与Vivaldi天线级联,并设计了金属腔隔离辐射和滤波两部分,有效降低了电磁干扰和交叉极化.测试结果显示:PIN二极管处于导通状态时,天线工作在25.9-28.6 GHz,最大增益为8.83 dBi;PIN二极管处于断开状态时,天线工作在32.6-35.9 GHz,最大增益为9.97 dBi;可重构中心频率比达到了1∶1.26,两个频带的交叉极化电平均低于-20 dB. 展开更多
关键词 毫米波天线 滤波天线 频率可重构 PIN二极管
在线阅读 下载PDF
上一页 1 2 87 下一页 到第
使用帮助 返回顶部