Current Location:home > Browse

1. chinaXiv:201905.00050 [pdf]

基于单极感应问题的多极感应实验

张学亮
Subjects: Physics >> Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics

针对单极感应之谜,本文注意到磁力线是闭合线,利用洛伦茨力概念首先证明N与M两种对立观点都能够合理解释自法拉第时期以来典型的、有较大影响的单极感应实验。并采用等效电路和比较简明的方法推演出单极感应实验测量回路中感应电动势的一般表达式,说明单极感应问题至今未果的原因是实验采用的轴对称磁体外围磁场特殊的对称性分布结构,且分布结构不随磁体旋转而改变造成的。也说明单极感应实验本身无法解决单极感应问题。介绍了一种多极感应实验方案与实验结果,结合实验磁体外围磁场分布状况,同样用N与M两种观点对照分析了实验结果,得出了法拉第与韦伯当年的单极感应实验测量回路中的感应电动势是由磁体外相对于实验室参照系静止的线段产生的结论,该结论与M观点的结论一致。

submitted time 2019-05-08 Hits4037Downloads312 Comment 0

2. chinaXiv:201904.00071 [pdf]

湍流手性:可逆系统的平衡与非平衡有螺系综

朱建州
Subjects: Physics >> Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics
Subjects: Physics >> Geophysics, Astronomy, and Astrophysics

研究基于修改Navier-Stokes方程而得到可逆守恒系统的有螺湍流研究思路和理论。讨论三维可压缩湍流统计力学分析及螺度控制力热声问题。构建了一个非平衡系综的有螺可逆系统。最后简要讨论工程应用。

submitted time 2019-03-31 Hits4681Downloads321 Comment 0

3. chinaXiv:201901.00071 [pdf]

Clinical study on Transcranial magnetoelectric encephalopathy treatment instrument treatmenting parkinson’s disease

Qiang Tang; Wei Zou; Zuodong Sun; Kang Li; Wuyi Sun; Wenhua Wang; Yanli Xing; Xueping Yu; Jing Bai; Xiuying Teng; Yan Hou
Subjects: Medicine, Pharmacy >> Clinical Medicine
Subjects: Physics >> Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics

[Objective] Evaluate on the treatment efficacy and safety for transcranial magnetoelectric encephalopathy treatment instrument (brand name: AOBO Parkinson’s Treatment Instrument) treatmenting parkinson's disease. [Methods] Use methods of double center,randomized, double blind, self crossover, 22 Parkinson’s patients who met the inclusion criteria were randomly divided into A group and B group, then were carried on the curative effect analysis, and were observed therapeutic effect. [Results] The treatment group of 22 cases, basically cured in 0 cases, markedly effective in 9 cases, effective in 8 cases, ineffective in 5 cases. The total efficiency rate and total effective rate were 40.91% (9/22) or 77.27% (17/22) respectively. The control group of 22 cases, basically cured in 0 cases, markedly effective in 2 cases, effective in 3 cases, ineffective in 17 cases. The total efficiency rate and total effective rate were 9.09% (2/22) or 22.73% (5/22) respectively, the total effective rate and total effective rate in the treatment group were higher than those in the control group, the difference was statistically significant (P<0.05). Among them, the main symptoms of resting tremor, rigidity, bradykinesia, evaluation, the treatment group has significant difference (P<0.01); There was no significant difference in the control group (p>0.05); There was significant difference between the treatment group and the control group (p<0.05). [Conclusions] Transcranial magnetoelectric stimulation can significantly improve resting tremor, muscle rigidity, bradykinesia in patients with Parkinson’s disease and other symptoms, and the use of safety. "

submitted time 2019-01-15 Hits7840Downloads433 Comment 0

4. chinaXiv:201901.00070 [pdf]

重复经颅磁电刺激对海人酸致痫鼠的疗效研究

张旺; 王孝义; 郭洪渠; 宋媛媛; 王爱丽; 孙作东; 沈红
Subjects: Medicine, Pharmacy >> Clinical Medicine
Subjects: Physics >> Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics

目的 探讨经颅磁电刺激(TMES)疗法对海仁酸(KA)致颞叶癫痫鼠的疗效。 方法 62只大鼠按照随机数字表法分为预处理组(共32只)和治疗组(共30只),预处理组再分为4个小组,分别给予治疗仪最大电流强度(MCI) 0%,25%,50%,75%的电流刺激,确定本实验条件下的最佳刺激参数。治疗组再分为3个小组,每组10只。2组(癫痫刺激组、癫痫非刺激组)为符合纳入标准的癫痫模型大鼠,刺激组刺激参数为预处理组确定出的最佳刺激参数;非刺激组大鼠刺激前后处理与刺激组相同,但治疗仪无有效的能量输出。第3组对照组为未造模对照大鼠。3组大鼠均给予每天1次,40 min/次,共14 d的刺激。记录并比较3组大鼠行为学、电生理学及组织学变化,以评估TMES疗法对癫痫大鼠的疗效。 结果 50%MCI为最佳刺激强度。癫痫刺激组大鼠癫痫波出现的频率明显低于癫痫非刺激组大鼠[(30.210 ±4.580)次/min vs. (31.380 ± 4.247)次/min],差异有统计学意义(t=3.235,P=0.001)。Timm染色结果提示3组大鼠染色评分差异有统计学意义(F=17.429, P=0.000),癫痫刺激组大鼠海马齿状回的内分子层Timm染色评分较癫痫非刺激组明显减轻,差异有统计学意义(P<0.05)。结论 TMES疗法可通过改善癫痫大鼠海马齿状回内分子层组织学变化程度来影响齿状回神经元环路的形成,进而降低癫痫脑电波的发作频率。

submitted time 2019-01-02 Hits4556Downloads435 Comment 0

5. chinaXiv:201811.00044 [pdf]

Fast_tracking_moving_object_using_single_pixel_imaging.pdf

时东锋
Subjects: Physics >> Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics

Successive images of a scene are captured and then further processed to achieve the moving object tracking. However, due to modulation rate limitations of the spatial light modulator in single-pixel imaging (SPI) system, the imaging frame rate cannot meet the high-resolution and real-time requirements for object tracking. In this paper, we demonstrate a fast object tracking technique based on SPI with an ultra-low sampling rate that is independent of imaging. We construct modulation information that satisfies the projection conditions and can transform 2D images into 1D projection curves. The 1D projection curves, which provide the location information of the moving object, can be obtained with high resolution in real-time, and then the tracking of the moving object is realized. A background subtraction technique for tracking moving objects that removes static components from a scene is also proposed. The proposed technique is verified by computational simulations and laboratory experiments. In the laboratory experiments, we demonstrate that the proposed method can be used to track moving objects with less than 0.2% of the measurements established by the Nyquist criterion, and it presents a resolution of 256×256 pixels at ~177 fps. The reported technique accelerates the tracking speed of SPI and provides an efficient strategy for remote sensing and biomedical applications.

submitted time 2018-11-11 Hits6565Downloads391 Comment 0

6. chinaXiv:201712.02150 [pdf]

Feasibility analysis of 1d carbon material in application of negative particle beam diagnostics.pdf

Xu,Yongjian
Subjects: Physics >> Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics

An important feature of China Fusion Engineering Test Reactor(CFETR) project is represented by the additional heating obtained from the injection of neutral beams based on accelerated negative ions. For the neutral beams based on negative ions, the most important measurements are beam uniformity, beamlet divergence and stripping losses. According to the CFETR requirement, the maximum allowed beam divergence angle and beam non-uniformity are 6 mrad and ±10%,respectively. As 1D carbon tiles have large ratio between perpendicular conductivity and parallel conductivity and high stability, they can be used for beam uniformity and beamlet divergence measurement. This paper presents the investigation of the influence on the response of 1D carbon tile having the thermal characteristics and features of some dedicated diagnostics. Simulations show that it will be possible to verify experimentally whether the beam meets the requirement about the maximum allowed value. This work lays a foundation for design and application of high precision beam diagnostic targets.

submitted time 2017-11-27 Hits10037Downloads802 Comment 0

7. chinaXiv:201712.01969 [pdf]

红外成像灰度随距离变化的李群表达

李晨曦; 史泽林; 刘云鹏
Subjects: Physics >> Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics
Subjects: Mathematics >> Mathematics (General)

大气对红外辐射传输的影响引起的红外成像灰度变化,是红外目标跟踪应用需要应对的问题。本文的研究目的是对红外成像灰度变化规律进行李群建模,对设计高效、鲁棒的目标跟踪算法有重要意义。首先分析了红外辐射传输模型,并结合红外成像机理,得到红外成像灰度变化模型。进一步从理论上证明了大气影响下红外成像灰度变化规律符合李群结构,提出了红外图像灰度动态变化的一种非欧数学表征。最后根据红外成像灰度变化模型对不同环境下采集到的外场实验数据进行拟合,回归分析结果表明了该模型的准确性,进而说明了本文对红外成像灰度变化规律进行李群表达的合理性。

submitted time 2017-11-26 Hits10871Downloads1609 Comment 0

8. chinaXiv:201710.00002 [pdf]

在液滴作用下悬浮薄膜的毛细皱纹标度律

孙博华
Subjects: Physics >> Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics

研究意义: 悬浮于液体的薄膜在其上有个液滴(drop),由于液滴的表面张力的作用,薄膜会发生皱纹。皱纹的长度和数量对于测量和标定薄膜材料的性能非常有意义。 J. Huang, M. Juszkiewicz, W. H. de Jeu, E. Cerda, T.Emrick, N. Menon and T. P. Russell在 Science, 317, 650(2007) 通过细致的实验,并通过曲线拟合得到了薄膜皱纹长度和数量的经验表达式,2010年D. Vella, M. Adda-Bedia and E. Cerda, Soft Matter 6,5778 (2010),利用圆形薄板理论进行了解析和数值分析,从理论上部分地验证了 Huang et al(2007)的经验公式。 存在的问题是: 1. 目前得到的经验表达式是否是普遍适用的结果? 2.如果不是普遍适用,那么在什么情况下可以使用这些经验公式? 3.目前的结果都是在各向同性薄膜的情况下获得的结果,那么对于正交各向同性薄膜的情况如何把现有表达式推广到正交各向同性薄膜? 4.Huang (2007), Vella (2010)和其他成果都是只是研究静态情况,而实际情况是,表面张力的作用是一个动力学的过程,随着时间的发展,皱纹长度和数量要发生变化,如何在静态成果的基础上,推广到皱纹动力学? 5.另外,液滴的半径如果超过毛细尺度,重力就起主导作用,就必须考虑重力的影响(之前的论文都没有考虑),这时的皱纹长度和数量与时间的关系满足什么标度律? 本文的工作: 首先我们使用量纲分析方法,推导出皱纹长度和数量的一般关系,发现皱纹长度和数量由二个组合无量纲参数的联合作用控制,在一般非线性变形的情况下,没有普遍适用的规律(标度律),只有在线性小变形的情况,才有普遍适用的标度律。 在小变形的情况下,皱纹长度主要有薄膜面内刚度与表面张力之比控制,其物理意义就是,在液滴薄膜张力一定的情况下,薄膜面内拉伸性能越好皱纹越长,反之,越短。皱纹数量取决于液滴的半径和薄膜弯曲刚度与表面张力之比,薄膜越容易弯曲皱纹越多,反之,越少。这里的结果完全符合物理观察。 对于小变形情况,我们把各向同性薄膜的情况推广到正交各向同性的情况。 对于皱纹动力学问题,我们利用Tanner的液滴半径随时间的标度律,结合我们得到的结果,成功地得到了皱纹长度和数量的动力学结果。以前没有看到皱纹动力学的结果。 最后,我们给出了重力主导的皱纹长度和数量的表达式,发现在重力主导的情况下,皱纹长度和数量对于给定的问题,是一个常数。以前没有看到重力主导情况下的皱纹结果。

submitted time 2017-09-30 Hits9870Downloads859 Comment 0

9. chinaXiv:201707.00135 [pdf]

Simultaneous fusion, imaging and encryption of multiple objects using a single-pixel detector

Shi Dongfeng; Huang Jian, Wang Yingjian, Yuan Kee, Xie Chenbo, Liu Dong and Zhu Wenyue
Subjects: Physics >> Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics

A novel technique for the simultaneous fusion, imaging and encryption of multiple objects using a single-pixel detector is proposed. Here, encoded multiplexing speckles are employed to illuminate multiple objects simultaneously. The mixed light reflected from the objects is detected by a single-pixel detector. An iterative reconstruction method is used to restore the fused image by summing the multiplexed speckles and detected intensities. Next, clear images of the objects are recovered by decoding the fused image. We experimentally obtain fused and multiple clear images by utilizing a single-pixel detector to collect the direct and indirect reflected light. Technically, by utilizing the speckles with per-pixel exposure control, multiple objects’ information is multiplexed into the detected intensities and then demultiplexed computationally under the single-pixel imaging and compressed sensing schemes. An encryption experiment is performed by setting the multiplexed speckles’ encoding as keys. We find that the encryption performance in a scattering medium is better than that in a clear medium.

submitted time 2017-07-13 Hits9870Downloads750 Comment 0

10. chinaXiv:201705.00860 [pdf]

基于Pulser-sustainer 放电的高重复频率长脉冲TE CO2 激光器持续运转特性

卢远添; 黄文武; 钟艳红; 刁伟伦; 柯长军; 吴谨
Subjects: Physics >> Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics

摘要:研究了一台长脉冲紫外预电离 TE CO2 激光器的长时间持续运转特性。激光器增益体积为 1.17L、采用摘要:研究了一台长脉冲紫外预电离 TE CO2 激光器的长时间持续运转特性。激光器增益体积为 1.17L、采用Pulser/sustainer 放电激励。在工作气体气压 30kPa、不采用固体催化剂的条件下,采用三种放电脉冲宽度(14.2us, 20.0us 和 24.5us) 和不同的注入能量,激光器分别连续不中断运转 30 分钟。详细记录了单脉冲放电时激光器的典型放电电压/电流波形和相应激光脉冲波形以及高重复频率工作时激光平均功率的实时变化曲线。数据显示,这种长脉冲 TE CO2激光器在不同放电脉冲宽度、不同注入能量、不同脉冲重复频率下均成功稳定运转 30 分钟,激光平均功率下降均小于 15%;同时,这种激光器在高重复频率运转时具备较好的“抗起弧”能力,偶尔的起弧放电不会雪崩发展至中断激光输出。研究结果表明,这种长脉冲 TE CO2激光器在高重复频率下具备良好持续运转能力。

submitted time 2017-05-18 Hits10391Downloads1220 Comment 0

12  Last  Go  [2 Pages/ 19 Totals]