基于波电耦合的路基边坡水毁隐患快速检测技术

文中针对我国当前的道路工程水毁多发类型,基于先进的无损检测技术即电阻率层析成像和波速层析成像检测技术,研究了路堤边坡、桥头锥(护)等典型结构水毁灾害发生前状态变化的电阻率与波速成像耦合的定量化检测和预评估技术,并应用于工程实际,丰富了路基水毁前隐患监测及预警技术。

填方地基压实质量的波电场耦合快速检测试验研究

土石填方地基的压实质量直接影响着上部结构的沉降变形和稳定性,如何有效地评价土石填方地基的压实质量是土石填方施工质量控制中亟待解决的关键技术问题。基于土石填料的波动传播特性和电阻率特性,构建了波电场耦合检测路基压实质量的理论模型,基于该模型提出了适用于填方地基现场压实质量检测的波电场耦合快速测试方法。将该方法应用于土石填方地基现场,采用面波测试的方法测试土石地基的波动信号,利用瑞利波的频散效应分析测试断面的横波波速,采用直流电阻率法采集测量断面的电阻率数据。对现场地基填料的波电场参数统计分析,构建了基于波电场耦合的填方地基压实度计算模型,利用现场测试的波电场参数对填方地基的压实质量进行了综合评价。结果表明,构建的模型综合了土石填料的波电场参数,应用过程中测试方便,计算简单,便于快速检测。

井孔周围轴对称声电耦合波:理论(I)

由于存在双电层，在孔隙地层中声波可引起渗透电流、流动电势及电磁场；电磁波也可以诱导渗流和声波。轴对称的声场（Ｐ—ＳＶ波）只产生轴对称的电磁场（ＴＭ 波），而轴对称的电场只产生轴对称的声场。在轴对称假设下，利用Ｐｒｉｄｅ声电耦合波控制方程和井壁上的边界条件，导出点声源激发的井内外声场和转换电磁场的计算公式、竖直电偶极子激发的井内外电磁场和转换声场的计算公式，并利用文内给出的公式对声电效应测井进行数值模拟。

井孔周围轴对称声电耦合波:声电效应测井数值模拟(Ⅱ)

胡恒山 ,王克协 .井孔周围轴对称声电耦合波 :声电效应测井数值模拟 ( ) .测井技术 ,2 0 0 0 ,2 4(1) :3～ 13在流体饱和的孔隙介质中存在声电耦合现象。作者已导出了井中点声源激发时井内、外声场和电磁场的表达式 [1 ] ,在此基础上给出数值算例 ,说明转换电磁场的基本特性 ,分析部分介质参数对声电转换波的影响。当位于井轴上的声源激发声波时 ,在流体饱和的孔隙地层中将不仅产生声波 ,而且产生与之耦合的电磁场。在井中 ,不仅可以接收到来自地层的声波 ,还可以接收到以电磁波速度传播、几乎同时达到不同源距的接收器的“电磁首波”和伴随声波的电磁场。井中接收到的转换电场的强弱 ,不仅取决于地层动电耦合系数 ,还取决于波的传播特性 ,特别是井孔的波导效应。文章考察了电声比与频率、接收位置、孔隙度、渗透率、井内外矿化度等的关系。当从接收声压曲线上可分辨出纵波、横波、斯通利波时 ,从转换电磁场也可以分辨出相应的波包。就电声比而言 ,纵波最大 ,斯通利波次之 ,横波最小。由于低频时动电耦合系数较大 ,更由于低频时斯通利波的激发强度显著增大 ,频率为 1k Hz时斯通利波转换电场的幅度约等于频率为 10 k Hz时幅度的 10 0倍 ,频率为 1k Hz时斯通利波的电声比约等于频率为 10 k Hz时的 5倍。

耦合腔慢波电路的三维软件冷测模拟(英文)

讨论了在考虑行波管管壳影响的情况下,使用MAFIA模拟软件软件的冷测方法模拟耦合腔慢波电路的高频特性参数,包括色散特性、耦合阻抗和衰减特性,使色散特性精度提高到0.29%,其模拟结果比忽略管壳影响下的计算值更加接近实验数据,也证明了计算机模拟冷测方法可以取代实验测试方法。

Ansys软件在行波管耦合腔慢波电路分析中的应用

利用ANSYS有限元软件对异型耦合槽、锥度漂移管以及带吸收小腔的多种耦合腔慢波电路进行三维电磁场仿真计算 ,通过进行单腔及多腔谐振模式分析 ,得到各种耦合腔慢波系统的色散关系曲线 ,数值计算结果与实验测试值非常吻合。同时 ,在ANSYS计算基础上结合区域匹配方法 ,提出了一种新的工程计算方法 ,在实际工程中使用具有很好的应用价值。

Analysis of input harmonic current mitigating performance in dual output phase-shift distribution transformer

A novel dual output phase-shift distribution transformer （ DOPSDT ） is proposed based on the electromagnetic filtering theory. First, its structural characteristics, winding connection mode and turn number ratio for special phase shifting are investigated. Secondly, the balance formulation of harmonic magneto-motive forces is derived and the electromagnetic filtering principle of the DOPSDT is introduced. The harmonic mitigating performance under different nonlinear load conditions are also analyzed using the field-circuit coupled method, The analysis results show that the DOPSDT can mitigate the primary current distortion even under severe nonlinear load conditions. By applying the zero sequence flux cancellation and phase-shift techniques at their secondary windings, the DOPSDT can significantly reduce the 3rd, 5th, 7th, 9th, 15th, 17th and 19th harmonics within its secondary windings.

Capacitive Microwave MEMS Switch

A novel capacitive microwave MEMS switch with a silicon/metal/dielectric as a membrane is fabricated successfully by bonding and etching-stop process. Its principal, design, and fabricating process are described in detail. A patterned dielectric layer, Ta2O5, with dielectric constant of 24 is reached. Experiment results show this novel structure,where the switch＇s dielectric layer is not prepared on the transmission line, features very low insertion loss. The insertion loss is 0.06dB at 2GHz and lower than 0.5dB in the wider range from De up to 20GHz,especially when the transmission line metal is only 0. 5μm thick.

The effect of Coriolis-Stokes forcing on upper ocean circulation in a two-way coupled wave-current model

We investigated the Stokes drift-driven ocean currents and Stokes drift-induced wind energy input into the upper ocean using a two-way coupled wave-current modeling system that consists of the Princeton Ocean Model generalized coordinate system (POMgcs), Simulating WAves Nearshore (SWAN) wave model, and the Model Coupling Toolkit (MCT). The Coriolis-Stokes forcing (CSF) computed using the wave parameters from SWAN was incorporated with the momentum equation of POMgcs as the core coupling process. Experimental results in an idealized setting show that under the steady state, the scale of the speed of CSF-driven current was 0.001 m/s and the maximum reached 0.02 m/s. The Stokes drift-induced energy rate input into the model ocean was estimated to be 28.5 GW, taking 14% of the direct wind energy rate input. Considering the Stokes drift effects, the total mechanical energy rate input was increased by approximately 14%, which highlights the importance of CSF in modulating the upper ocean circulation. The actual run conducted in Taiwan Adjacent Sea (TAS) shows that: 1) CSF-based wave-current coupling has an impact on ocean surface currents, which is related to the activities of monsoon winds; 2) wave-current coupling plays a significant role in a place where strong eddies present and tends to intensify the eddy's vorticity; 3) wave-current coupling affects the volume transport of the Taiwan Strait (TS) throughflow in a nontrivial degree, 3.75% on average.

Trace Elements in Leccinum scabrum Mushrooms and Topsoils from K odzka Dale in Sudety Mountains, Poland

In the current study, we determined concentrations and transfer rates of Ag, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, P, Rb, Sr and Zn to Brown Birch Scaber Stalks （Leccinum scabrum） mushrooms emerged in the area of Sudety Mountains （Sudetes） in Poland. Fruiting bodies and topsoil samples beneath L. scabrum were collected form the Ktodzka Dale. The trace elements were determined using validated method and inductively coupled plasma - atomic emission spectroscopy （ICP-AES） for final measurement. Mushrooms contained Ag, Cr, Hg, Co, Ni and Sr at 〈 1.0μg/g dry weight; Ba and Pb at -1.0μg/g dw; Cd at 〈 5μPg/g dw; Cu and Mn at 〉 10 μg/g dw; Al and Ca at -100μg/g dw; Fe, Na, Rb and Zn at lOO to 500μg/g dw, Mg at -1.000μg/g dw; P at -5,000 μg/g dw and K at -30,000 μg/g dw. Ca, Mn and Ni were nearly equally distributed between stipes and caps; stipes compared to caps were enriched in Ba, Na and Sr, while caps were enriched in Ag, Al, Cd, Co, Cr, Cu, Fe, K, P, Pb, Rb and Zn. The values of bioconcentration factor （BCF） varied highly depending on chemical element and were 〉1 for Ag, Cd, Cu, K, Mg, Na, P, Rb and Zn, while 〈1 for A1, Ba, Ca, Co, Cr, Fe, Mn, Ni, Pb and Sr. Topsoil showed elevated content of lead and mean concentration was 99 ± 32 μg/g dw, while cadmium was at 0.41 ± 0.15 and those two highly toxic to human elements occurred in edible caps of L. scabrum at 4.5 ± 2.2 and 2.9 ± 2.0 μg/g dw, respectively.

Mineral Constituents in Common Chanterelles and Soils Collected from a High Mountain and Lowland Sites in Poland

This paper reported the results of the determination of Ag, A1, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, Rb, Sr and Zn in Common Chanterelles （Cantharellus cibarius） Fr. and surface soil layer （o-io cm） underneath the fruiting bodies. Mushrooms and soils were collected from a lowland site in the Hel Peninsula （Baltic Sea coast） and a high mountain site in the Tatra Mountains. The trace elements were determined using validated method and inductively coupled plasma - atomic emission spectroscopy （ICP-AES）. Common Chanterelles that emerged at sites poor in mineral nutrients podzols of the Hel Peninsula forests efficiently bioeoncentrated several essential trace elements （K, P, Co, Cu, Mn, Na, Zn）, while the abundance of those elements in carpophores was around half less compared to specimens from Zakopane region and which emerged in soils much richer in minerals. Common Chanterelles collected at two spatially distant background areas in Poland were only weakly contaminated with metals such as Ag, Cd, Hg and Pb. The maximum tolerable Cd and Pb contents of certain cultivated mushrooms are regulated in the European Union by law and these hazardous metals in C. cibarius were far below tolerance limits set.

Interaction of a Surface Acoustic Wave with a Two-dimensional Electron Gas

When a surface acoustic wave （SAW） propagates on the surface of a GaAs semiconductor, coupling between electrons in the two-dimensional electron gas beneath the interface and the elastic host crystal through piezoelectric interaction will attenuate the SAW. The coupling coemcient is ~alculated for the SAW propagating along an arbitrary direction. It is found that the coupling strength is strongly dependent on the propagating direction. When the SAW propagates along the [011] direction, the coupling becomes quite weak.

Persistent Spin Current in a Hard-Wall Confining Quantum Wire with Weak Dresselhaus Spin-Orbit Coupling

We investigate theoretically the spin current in a quantum wire with weak Dresselhaus spin-orbit coupling connected to two normal conductors. Both the quantum wire and conductors are described by a hard-wall confining potential. Using the electron wave-functions in the quantum wire and a new definition of spin current, we have calculated the elements of linear spin current density j^Ts,xi and j^Ts,yi（i=x, y, z）. We find that the elements j^Ts,xx and j^Ts,yy have a antisymmetrical relation and the element j^Ts,yz has the same amount levelas j^Ts,xx and j^Ts,yy. We also find a net linear spin current density, which has peaks at the center of quantum wire. The net linear spin current can induce a linear electric field, which may imply a way of spin current detection.

Research on main circuit parameter coupling relationship of single-phase shunt active power filter

There is a certain coupling relationship among the main circuit parameters of a single-phase shunt active power filter(SAPF),which has a great influence on the reasonable selection of various parameter values.By analyzing the calculation methods of the inductance of alternating current(AC)side and the voltage and capacitance values of direct current(DC)side in the existing single/three-phase SAPF main circuit,a specific single-phase SAPF circuit parameter analytical expression was obtained.Aiming at the coupling relationship among the variables in the resulting expression,the model was optimized and analyzed in MATLAB,and a complete set of parameters design scheme was obtained,which ensure the comprehensive optimization target of the post-harmonic content below 2% is compensated under a specific load.The simulation and experimental procedures verify the correctness of the selected parameters.

An attitude algorithm based on the band seamless splicing imaging for agile satellite

In order to realize fast maneuvering imaging of the target area with high resolution agile satellite, a new attitude matching algorithm is developed. A strict mosaic imaging model of ray trace and the velocity vector mapping are built according to the strip mosaic imaging principle and the relationship between imaging target and the camera focal plane. The three-axis attitude is deduced based on the principle of optimal tracking of the maneuvering path. Finally, the geometric scaling simulation is carried out through the time delayed and integration(TDI) charge coupled device(CCD) prototype system, satellite attitude control physical simulation platform and the LED earth target simulator. The experimental results show that the algorithm could realize the matching band seamless splicing imaging of the target very well, confirming the correctness of the algorithm.

Quantitative analysis of elements (C,N,O,Al,Si and Fe) in polyamide with wavelength dispersive X-ray fluorescence spectrometry

A wavelength dispersive X-ray fluorescence （WD-XRF） spectrometry combined with calibration curve method was estab- lished for simultaneously analyzing low-Z elements （C, N, O） and A1, Si, Fe in polyamide. To investigate the origin of plastic material causing deposition and blocking in instrument engines and pipelines, polyamide 6 （PA 6, an engineering plastic） was chosen as the study object on account of its common use in industry. The sample preparation with pressed powder disk has been developed for determination of six elements in PA 6. Pure Cu metal was used as the matrix and PA 6 was regarded as standard sample for C, N, O elements. PA 6 particles were firstly smashed to uniform powder in liquid nitrogen, and then mixed with inorganic standard powders （Fe203, A1203, SIO2, and Na2SiO3）. The mixture was ground to obtain homogeneous calibration materials for WD-XRF analysis. The quantitative property of the calibration curve method for each element was re- liable. The limits of detection （S/N≤3） of C, N, O, A1, Si and Fe using WD-XRF were 249, 120, 101, 6.2, 3.3, and 1.8 μg/g, respectively. To confirm the accuracy of the proposed WD-XRF calibration curve method, inductively coupled plasma optical emission spectroscopy （ICP-OES） detection for A1, Si, Fe and elemental analyzer （EA） analysis for C, N, O were utilized. A good correlation of the WD-XRF results with the measurements of ICP-OES and EA was observed.