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高温超导量子干涉器在无损检测中的应用研究 被引量:5
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作者 丁红胜 孙景春 +2 位作者 何豫生 张峰会 陈赓华 《测试技术学报》 EI 2004年第4期311-315,共5页
 研制了一套可长时间稳定工作在无屏蔽环境中的高温超导量子干涉器(SQUID)无损检测装置,其中SQUID由Yba2Cu3O7(YBCO)制成.为了减小低频噪声,SQUID器件采用多圈条形结构,膜条宽度8μm,膜条间隔10μm,器件的有效面积为0.01mm2,在无屏蔽...  研制了一套可长时间稳定工作在无屏蔽环境中的高温超导量子干涉器(SQUID)无损检测装置,其中SQUID由Yba2Cu3O7(YBCO)制成.为了减小低频噪声,SQUID器件采用多圈条形结构,膜条宽度8μm,膜条间隔10μm,器件的有效面积为0.01mm2,在无屏蔽环境中的磁通白噪声约为200μΦ0/Hz.利用该装置对有内部缺陷的铝样品进行了电磁无损检测实验研究,并对激励频率与缺陷深度、缺陷大小与信号响应之间的关系进行了初步的探讨. 展开更多
关键词 屏蔽环 SQUID 低频噪声 器件 量子干涉 白噪声 有效面积 高温超导 磁通 YBCO
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高温直流超导量子干涉器心磁图仪的研制 被引量:4
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作者 丁红胜 陈赓华 +2 位作者 张利华 黄旭光 杨乾声 《北京科技大学学报》 EI CAS CSCD 北大核心 2006年第9期863-866,共4页
研制了用于心磁测量的直流高温量子干涉器,并建立了单通道高温直流超导量子干涉器心磁图仪.根据临床诊断标准,在磁屏蔽室内依次调节无磁床的位置,采集了人体胸前平面5×5正方格子上各点的心磁数据.实验结果表明,健康人与心脏病患者... 研制了用于心磁测量的直流高温量子干涉器,并建立了单通道高温直流超导量子干涉器心磁图仪.根据临床诊断标准,在磁屏蔽室内依次调节无磁床的位置,采集了人体胸前平面5×5正方格子上各点的心磁数据.实验结果表明,健康人与心脏病患者的心脏磁场信号存在明显差异.利用该系统,可为心脏病的临床诊断提供有价值的实验数据. 展开更多
关键词 高温超导量子干涉器 心磁图仪 心磁测量 磁场信号
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高温超导心磁图仪临床应用的初步研究 被引量:1
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作者 王自强 陈惟昌 +3 位作者 杨乾声 陈赓华 张利华 黄旭光 《中日友好医院学报》 2006年第5期284-286,共3页
目的:介绍我们合作研制的高温超导心磁图仪(HT-MCG)的原理、性能及其临床的初步应用。方法:应用高温超导量子干涉器研制成HT-MCG,并开发配套的心磁图分析软件。结果:对50例正常人进行测试,结果表明,该HT-MCG的性能已能满足临床应用的要... 目的:介绍我们合作研制的高温超导心磁图仪(HT-MCG)的原理、性能及其临床的初步应用。方法:应用高温超导量子干涉器研制成HT-MCG,并开发配套的心磁图分析软件。结果:对50例正常人进行测试,结果表明,该HT-MCG的性能已能满足临床应用的要求,测试结果满意。结论:HT-MCG价格较低,性能已能满足临床需要,有良好的应用前景。 展开更多
关键词 高温超导量子干涉器 心磁图仪 等磁场图
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用于室温样品的扫描SQUID显微镜的研制
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作者 丁红胜 何豫生 +4 位作者 张峰会 韩士吉 董世迎 陈赓华 于洪伟 《应用科学学报》 CAS CSCD 2004年第4期528-532,共5页
成功制备了用于室温样品磁测量的扫描SQUID显微镜.SQUID利用YBCO薄膜制成,并安装在双层杜瓦内胆的底部冷指端.为了提高系统的空间分辨率,杜瓦设计了特殊的微调装置和白宝石窗口.该显微镜可在无屏蔽环境中工作,其磁场灵敏度约为46pT/Hz1... 成功制备了用于室温样品磁测量的扫描SQUID显微镜.SQUID利用YBCO薄膜制成,并安装在双层杜瓦内胆的底部冷指端.为了提高系统的空间分辨率,杜瓦设计了特殊的微调装置和白宝石窗口.该显微镜可在无屏蔽环境中工作,其磁场灵敏度约为46pT/Hz1/2,空间分辨率优于500μm.利用该显微镜成功实现了室温样品的弱磁测量,并进行了无损检测的应用研究. 展开更多
关键词 高温超导量子干涉器 磁测量 显微镜 无损检测 凝聚态物理学
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基于高温DC-SQUID的低场核磁共振仪
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作者 李绍 储海峰 +4 位作者 田野 任育峰 陈莺飞 陈赓华 郑东宁 《稀有金属材料与工程》 SCIE EI CAS CSCD 北大核心 2008年第A04期362-365,共4页
研制了一套基于高温DC-SQUID的低场核磁共振仪(NMR)。它由磁场系统,系统控制软件和DC-SQUID测量仪器组成。首先,由磁场计算值设计和制作了SQUID低场NMR的磁场系统(各个线圈的几何尺寸及其相对位置);然后,用LabVIEW编写了测量系统的控制... 研制了一套基于高温DC-SQUID的低场核磁共振仪(NMR)。它由磁场系统,系统控制软件和DC-SQUID测量仪器组成。首先,由磁场计算值设计和制作了SQUID低场NMR的磁场系统(各个线圈的几何尺寸及其相对位置);然后,用LabVIEW编写了测量系统的控制程序,实现了系统参数的控制测量和数据采集的自动化;最后,联合调试使测量系统满足原先设计的要求。经核实和多次重复测量证明各部件的性能很好并能按设计的要求工作。磁场的测量值在理论计算值的误差范围之内:预极化场可以达到10mT,测量磁场可以在200μT和1μT之间调节。更进一步的测试和分析还在进行中。 展开更多
关键词 核磁共振 超导量子干涉仪 LABVIEW
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全铌隧道结的工艺以及dcSQUID研究 被引量:1
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作者 杨乾声 陈赓华 +2 位作者 杜寰 赵士平 徐凤枝 《低温工程》 CAS CSCD 北大核心 1999年第4期305-309,共5页
用磁控溅射方法及选择铌阳极氧化和选择铌刻蚀工艺制备了 Nb/ Al Al Ox/ Nb 全铌隧道结, 给出了工艺要点。根据全铌结的参量, 设计了全铌隧道结dc S Q U I D。制成的dc S Q U I D的传输函数δ V/δ~... 用磁控溅射方法及选择铌阳极氧化和选择铌刻蚀工艺制备了 Nb/ Al Al Ox/ Nb 全铌隧道结, 给出了工艺要点。根据全铌结的参量, 设计了全铌隧道结dc S Q U I D。制成的dc S Q U I D的传输函数δ V/δ~14 m V/0,其本征能量分辨率达到24 h。 展开更多
关键词 全铌隧道结 SQUID 直流 超导量子干涉器
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Fabrication of high-quality submicron Nb/Al-AlO_x/Nb tunnel junctions 被引量:2
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作者 于海峰 曹文会 +6 位作者 朱晓波 杨海方 于洪伟 任育峰 顾长志 陈赓华 赵士平 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第8期3083-3086,共4页
Nb/Al-AlOx/Nb tunnel junctions are often used in the studies of macroscopic quantum phenomena and superconducting qubit applications of the Josephson devices. In this work, we describe a convenient and reliable proces... Nb/Al-AlOx/Nb tunnel junctions are often used in the studies of macroscopic quantum phenomena and superconducting qubit applications of the Josephson devices. In this work, we describe a convenient and reliable process using electron beam lithography for the fabrication of high-quality, submicron-sized Nb/Al-AlOx/Nb Josephson junctions. The technique follows the well-known selective Nb etching process and produces high-quality junctions with Vm=100 mV at 2.3 K for the typical critical current density of 2.2 kA/cm^2, which can be adjusted by controlling the oxygen pressure and oxidation time during the formation of the tunnelling barrier. We present the results of the temperature dependence of the sub-gap current and in-plane magnetic-field dependence of the critical current, and compare them with the theoretical predictions. 展开更多
关键词 Nb junctions FABRICATION superconducting qubit macroscopic quantum phenomena
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呼和浩特地铁2号线气象局站深基坑变形规律分析
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作者 陈赓华 《工程机械与维修》 2021年第5期179-181,共3页
针对呼和浩特地铁2号线气象局站周边存在较为密集的建筑及管线,为了保证施工安全,基于现场实测数据研究施工过程中地铁基坑的变形规律,结果表明:本工程选用的支撑方式可满足施工要求;基坑施工过程中时空效应较为明显,应注意开挖顺序;基... 针对呼和浩特地铁2号线气象局站周边存在较为密集的建筑及管线,为了保证施工安全,基于现场实测数据研究施工过程中地铁基坑的变形规律,结果表明:本工程选用的支撑方式可满足施工要求;基坑施工过程中时空效应较为明显,应注意开挖顺序;基坑周边的材料堆放和机械振动等均会加剧基坑及周边土体的明显变形。 展开更多
关键词 地铁施工 沉降变形 深基坑
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A Novel Filter Scheme of Data Processing for SQUID-Based Magnetocardiogram 被引量:1
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作者 刘当婷 田野 +4 位作者 任育峰 于洪伟 张利华 杨乾声 陈赓华 《Chinese Physics Letters》 SCIE CAS CSCD 2008年第7期2714-2717,共4页
We present a new filter scheme for magnetocardiogram (MCG) signal processing based on the quasi-periodic characteristic of the signals. The key points of this scheme are to determine the exact numbers of data points... We present a new filter scheme for magnetocardiogram (MCG) signal processing based on the quasi-periodic characteristic of the signals. The key points of this scheme are to determine the exact numbers of data points in each cardiac cycle by using electrocardiogram (ECG) data acquired simultaneously with the MCG signal and to normalize the MCG data sequence in each cycle into an identical length. Compared with conventional filters, the scheme has the advantage of more powerful noise suppression with less signal distortion. The desire for having high quality output signals from raw MCG data acquired in a simple shielded room or even in unshielded environment may be realized with the scheme. 展开更多
关键词 the power-law exponents PRECIPITATION durative abrupt precipitation change
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Nb/Al-AlO_x/Nb junctions with controllable critical current density for qubit application 被引量:1
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作者 曹文会 于海峰 +4 位作者 田野 于洪伟 任育峰 陈赓华 赵士平 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第11期5044-5046,共3页
Nb/Al-AlOx/Nb tunnel junctions with controllable critical current density Jc are fabricated using the standard selective Nb etching process. Tunnel barriers are formed in different oxygen exposure conditions (oxygen ... Nb/Al-AlOx/Nb tunnel junctions with controllable critical current density Jc are fabricated using the standard selective Nb etching process. Tunnel barriers are formed in different oxygen exposure conditions (oxygen pressure P and oxidation time t), giving rise to Jc ranging from 100A/cm^2 to above 2000A/cm^2. Jc shows a familiar linear dependence on P×t in logarithmic scales. We calculate the energy levels of the phase- and flux-type qubits using the achievable junction parameters and show that the fabricated Nb/Al-AlOx/Nb tunnel junctions can be used conveniently for quantum computation applications in the future. 展开更多
关键词 Nb junctions FABRICATION superconducting qubit macroscopic quantum state
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超导弱连接中的Josephson电流在一个磁通量子内的振荡(Ⅰ) Josephson结
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作者 张裕恒 陈赓华 《物理学报》 SCIE EI CAS 1982年第6期749-757,共9页
本文指出如果Josephson结处在Q值足够高的谐振腔内,当Josephson频率ω=2eV_0/h与谐振腔的本征频率ω_r发生谐振时,谐振的电磁场对Josephson结自身的反馈作用将导致超流电流在一个磁通量子内随磁场的小周期振荡。
关键词 谐振腔 本征模 磁通量子 JOSEPHSON 电流
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Phase escape of current-biased Josephson junctions
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作者 曹文会 于海峰 +2 位作者 田野 陈赓华 赵士平 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第6期503-506,共4页
Switching current distributions of an Nb/Al-AlO2/Nb Josephson junction are measured in a temperature range from 25 mK to 800 mK. We analyse the phase escape properties by using the theory of Larkin and Ovchinnikov (L... Switching current distributions of an Nb/Al-AlO2/Nb Josephson junction are measured in a temperature range from 25 mK to 800 mK. We analyse the phase escape properties by using the theory of Larkin and Ovchinnikov (LO) which takes discrete energy levels into account. Our results show that the phase escape can be well described by the LO approach for temperatures near and below the crossover from thermal activation to macroscopic quantum tunneling. These results are helpful for further study of macroscopic quantum phenomena in Josephson junctions where discrete energy levels need to be considered. 展开更多
关键词 Nb junctions phase escapes macroscopic quantum phenomena discrete energy levels
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Quantum Spontaneous Magnetization in Single-Junction Superconducting π-Rings
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作者 田野 朱学敏 +2 位作者 刘当婷 赵士平 陈赓华 《Chinese Physics Letters》 SCIE CAS CSCD 2008年第10期3757-3760,共4页
Based upon the calculations of energy levels and quantum states, we discuss the probability of quantum spontaneous magnetization flux as a function of the screen parameter β for the superconducting ring containing on... Based upon the calculations of energy levels and quantum states, we discuss the probability of quantum spontaneous magnetization flux as a function of the screen parameter β for the superconducting ring containing one Josephson π-junction, and compare the result with that in the classical case. Our results indicate that there is significant difference in the magnetization behaviour aroundβ = 1 between the quantum and classical situations. 展开更多
关键词 the power-law exponents precipitation durative abrupt precipitation change
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Research on high-Tc SQUID based non-destructive evaluation 被引量:1
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作者 王会武 孔祥燕 +8 位作者 任育峰 于洪伟 丁红胜 赵士平 陈赓华 周岳亮 张利华 何豫生 杨乾声 《Chinese Physics B》 SCIE EI CAS CSCD 2004年第1期19-23,共5页
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Magnetic field induced phase branches of the superconducting transition in two-dimensional square π-loop arrays
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作者 刘当婷 田野 +1 位作者 陈赓华 杨乾声 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第1期311-316,共6页
Based on the results of explicit forms of free energy density for each possible arrangement of magnetization fluxes in large-scale two-dimensional (2D) square π-loop arrays given by Li et al [2007 Chin. Phys. 16 14... Based on the results of explicit forms of free energy density for each possible arrangement of magnetization fluxes in large-scale two-dimensional (2D) square π-loop arrays given by Li et al [2007 Chin. Phys. 16 1450], the field-cooled superconducting phase transition is further investigated by analysing the free energy of the arrays with a simplified symmetrical model. Our analytical result is exactly the same as that obtained in Li's paper by means of numerical calculations. It is shown that the phase transition splits into two branches with either ferromagnetic or anti-ferromagnetic flux ordering, which depends periodically on the strength of external magnetic flux φe through each loop and monotonically on the screen parameter β of the loops in the arrays. In principle, the diagram of the phase branches is similar to that of its one-dimensional counterpart. The influence of thermal fluctuation on the flux ordering during the transition from normal to superconducting states of the π-loop arrays is also discussed. 展开更多
关键词 Josephson junctions π-loop arrays phase branches
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Analysis of Step Etching on SrTiO_(3) Substrates for the Step-Edge YBCO Josephson Junctions
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作者 CHEN Geng-Hua WANG Jing +3 位作者 ZHAO Shi-Ping HAN Bing XU Feng-Zhi YANG Qian-Sheng 《Chinese Physics Letters》 SCIE CAS CSCD 2001年第1期106-108,共3页
A way to determine some important etching parameters in the step fabrication for highTc step-edge Josephson junctions is described based on an analysis of the dynamics of the etching process.The optimum thickness of t... A way to determine some important etching parameters in the step fabrication for highTc step-edge Josephson junctions is described based on an analysis of the dynamics of the etching process.The optimum thickness of the etch mask is defined with negligible recession of the mask edge during the etch.Under this condition,the equilibrium angle of the steps etched on the SrTiO_(3)(STO)substrate with an Nb mask has been calculated to be about 76°.With optimized mask thickness,its sharp sidewall and straight edge,high-quality steps on STO substrates with step height from 200-300 nm and step angle above 70°are made.Josephson junctions and dc-SQUIDs with high reproducibility and less parameter scatter are obtained on the step substrates. 展开更多
关键词 process. JOSEPHSON STEPS
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Singular value decomposition with normalized period for magnetocaridiography signal processing
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作者 李倬 刘当婷 +4 位作者 田野 陈赓华 张利华 杨乾声 冯稷 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第10期2913-2917,共5页
In this paper, we have developed an algorithm based on singular value decomposition (SVD) for matrix. And the novel SVD algorithm with normalized period of cardiac cycles is presented. The results from real magnetoc... In this paper, we have developed an algorithm based on singular value decomposition (SVD) for matrix. And the novel SVD algorithm with normalized period of cardiac cycles is presented. The results from real magnetocardiography (MCG) data processing show that the new algorithm is better than the standard one not only in suppressing noises, but also in providing high-fidelity MCG signals. 展开更多
关键词 singular value decomposition MAGNETOCARDIOGRAPHY
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An NLMS algorithm with optimized preparatory step-size parameters for SQUID-based MCG data processing
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作者 李倬 陈赓华 +2 位作者 张利华 杨乾声 冯稷 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第2期310-314,共5页
We present a new least-mean-square algorithm of adaptive filtering to improve the signal to noise ratio for magneto-cardiography data collected with high-temperature SQUID-based magnetometers. By frequently adjusting ... We present a new least-mean-square algorithm of adaptive filtering to improve the signal to noise ratio for magneto-cardiography data collected with high-temperature SQUID-based magnetometers. By frequently adjusting the adaptive parameter a go systematic optimum values in the course of the programmed procedure, the convergence is accelerated with a highest speed and the minimum steady-state error is obtained simultaneously. This algorithm may be applied to eliminate other non-steady relevant noises as well. 展开更多
关键词 MAGNETOCARDIOGRAPHY optimal step size
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Retrieval of original signals for superconducting quantum interference device operating in flux locked mode
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作者 刘当婷 田野 +2 位作者 赵士平 任育峰 陈赓华 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第4期421-424,共4页
We discuss a simple relation between the input and output signals of a superconducting quantum interference device magnetometer operating in flux locked mode in a cosine curve approximation. According to this relation... We discuss a simple relation between the input and output signals of a superconducting quantum interference device magnetometer operating in flux locked mode in a cosine curve approximation. According to this relation, an original fast input signal can be easily retrieved from its distorted output response. This technique can be used in some areas such as sensitive and fast detection of magnetic or metallic grains in medicine and food security checking. 展开更多
关键词 SQUID magnetometer signal retrieval
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Microwave Response of Bi2Sr2CaCu2O8+δ Surface Intrinsic Josephson Junctions with Bending Pancake Vortices
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作者 魏彦锋 赵士平 +4 位作者 朱晓波 陈赓华 任育峰 于洪伟 杨乾声 《Chinese Physics Letters》 SCIE CAS CSCD 2007年第6期1709-1712,共4页
We study the microwave response of surface intrinsic Josephson junctions on Bi2Sr2 CaCu2O8+δ, in which bending pancake vortex lines are introduced in a controllable way. It is found that the bending vortices can gre... We study the microwave response of surface intrinsic Josephson junctions on Bi2Sr2 CaCu2O8+δ, in which bending pancake vortex lines are introduced in a controllable way. It is found that the bending vortices can greatly influence the response. In some cases, typical Shapiro steps that lie far above the quasiparticle branch are observed, with the step interval satisfying the Josephson relation and their amplitude versus the square root of microwave power following the Bessel function behaviour. In the other cases, current steps that lie on the quasiparticle branch are observed, but only one or two steps appear at the same time under the variation of the microwave power. 展开更多
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