A hybrid inversion method of damped least squares with simulated annealing used for Rayleigh wave dispersion curve inversion

Surface wave methods are becoming increasingly popular in many geotechnical applications and in earthquake seismology due to their noninvasive characteristics.Inverse surface wave dispersion curves are a crucial step in most surface wave methods.Many inversion methods have been applied to surface wave dispersion curve inversion,including linearized inversion and nonlinearized inversion methods.In this study,a hybrid inversion method of Damped Least Squares(DLS) with Very Fast Simulated Annealing(VFSA) is developed for multi-mode Rayleigh wave dispersion curve inversion.Both synthetic and in situ fi eld data were used to verify the validity of the proposed method.The results show that the proposed method is superior to the conventional VFSA method in aiming at global minimum,especially when parameter searching space is adjacent to real values of the parameters.The advantage of the new method is that it retains both the merits of VFSA for global search and DLS for local search.At high temperatures,the global search dominates the runs,while at a low temperatures,the local search dominates the runs.Thus,at low temperatures,the proposed method can almost directly approach the actual model.

Wave-Current Forces on Small Square Cylinders (Part I)

-Based on the extended Morison Equation and model tests, the in-line forces on small square cylinders caused by waves (regular and irregular) and currents are analyzed in detail in this paper. The hydrodynamic coefficient CD and Cu related to KC number and the effect of direction of wave incidence are also given, which can be used in engineering practice.

Square Wave Voltammetry for Analytical Determination of Cadmium in Natural Water Using Ca10(PO4)6(OH)2-Modified Platinum Electrode

This paper reports on the development of a novel electrochemical assay for cadmium (II) in natural water, which involves the use of disposable hydroxyapatite modified platinum electrode (HAP/Pt). Cadmium (II) was preconcentrated on the surface of the modified electrode and adsorbed onto HAP and oxidized at E = –680 mV. The HAP-modified platinum electrode exhibited superior performance in comparison to the plati- num electrode and surprisingly, yielded a higher electrochemical response. The best defined anodic peak was obtained with 0.2 mol L-1 KNO3 pH 5.0 after 25 min of accumulation time. Using these conditions, the cali- bration plot was linear over the range 1 × 10?8 to 5 × 10?6 mol L-1 Cd2+. The precision was examined by car- rying out eight replicate measurements at a concentration of 2.5 ×10?5 mol L-1;the coefficient of variation was 2.9%. The method was applied to the determination of the analyte in river water samples. The interfere- ence of other metal ions on the voltammetric response of Cd(II) was studied. The HAP films was clearly ob- served in the SEM images and characterized by X-ray diffraction, IR spectroscopy and chemical analysis.

Research on Vibration Suppression of the Finite Plate with Square Steel Beams Using Traveling Wave Method

The vibration suppression of the finite plate with square steel beams is studied using traveling wave method. The finite plate with square beams is modeled as the coupling systems between the plate flexural motion and the flexural and torsional motions for the square beams. The vibration response at any position of the coupling structure can be obtained by wave method. Numerical results show that comparing to finite element method (FEM), not only the low frequency but also the medium-high frequency vibration response of the finite plate with square beam can be effectively calculated by wave method. The suppression effect can be increased as the square beam is located at one-third of the length of plate or increasing the height of the beam. The study provides reference for arranged square beams applying to vibration suppression of ship and train structures.

Research on Fault-tolerant Operation Strategy of Rectifier of Square Wave Motor in Wind Power System

In wind power system,the randomness of wind energy increases the probability of components fault.once the switch fault of the PWM rectifier is detected,it will lead to the distortion of the motor voltage and current waveform,the increase of torque ripple,the fluctuation of filter capacitor voltage,and the increase of harmonic content,which will affect the control performance and operation safety of the system.A common fault in a three-phase PWM rectifier is the open-circuit fault of the switch.This paper analyzes the current waveform distortion of the square wave motor when the rectifier switch fault,and proposes different fault-tolerant control strategies for different situations of switch fault,include single,double and triple switches fault.This method is based on several special driving modes under power generation situation of square wave motor.The strategy is easy to implement and does not need to change the circuit topology.It can realize fault-tolerant control of switch faults in the same side half bridge or the same bridge arm of the three-phase PWM rectifier.The effectiveness of the proposed fault-tolerant strategy is verified by simulation and experiment at the end of the article.

Calculation of Significant Wave Height Using the Linear Mean Square Estimation Method

Significant wave height is an important criterion in designing coastal and offshore structures.Based on the orthogonality principle, the linear mean square estimation method is applied to calculate significant wave height in this paper.Twenty-eight-year time series of wave data collected from three ocean buoys near San Francisco along the California coast are analyzed.It is proved theoretically that the computation error will be reduced by using as many measured data as possible for the calculation of significant wave height.Measured significant wave height at one buoy location is compared with the calculated value based on the data from two other adjacent buoys.The results indicate that the linear mean square estimation method can be well applied to the calculation and prediction of significant wave height in coastal regions.

A Novel Square-wave Pulse Rotation Modulation Strategy for Modular Multilevel Converters

悬浮直流电容电压的均衡问题是模块组合多电平变换器（modular multilevel converter,MMC）的关键问题之一。提出一种可实现MMC直流电容电压平衡的方波脉冲循环调制（square-wave pulse rotation modulation,SWPRM）策略,在保证合成的阶梯波输出波形不变的前提下,根据MMC的拓扑结构和工作原理,对传统方波脉冲列进行脉冲优化,并按照一定的次序和切换周期进行循环和判断反相调整,获得的循环方波脉冲列作为最终驱动脉冲用于实现对MMC的控制。实验结果表明,采用提出的方波脉冲循环调制策略无需任何电容电压控制措施,在较低开关频率下,实现了MMC各功率单元间有功能量的平均分配和直流电容电压的均衡。

Deposition of cerium contained conversion films on LC4 alloy with square wave pulse method

Cerium contained conversion films were deposited on LC4 aluminum alloy using square wave pulse (SWP) in a CeC13 solution with KMnO4 as the oxidant. Energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM) were adopted to study the composition and the morphology of the film. It is found that the film is composed of Al, Zn, Cu,and small amount of cerium. The polarization curves of the specimens treated with SWP technique measured in 3.5% (mass fraction) NaCl solution reveal that the film thus formed inhibits both the anodic and cathodic process of the corrosion of the specimen. The immersion tests of treated specimens in 3.5% NaCl solution indicate that the corrosion resistance of the SWP treated specimen is better than that of the untreated and is equivalent to or even better than that of the traditionally electrochemically treated specimens.

A Square Wave Based Electrical Method for Human Skin Moisture Assessment

The moisture content measurement of human skin is a significant way to assess skin conditions and diagnose diseases that influence skin function.The necessity of evaluating the efficacy of a cosmetic product makes it important to improve the accuracy and reproducibility of the measurement.A pair of interdigitated gold electrodes was fabricated on the printed circuit board (PCB) substrate and utilized directly in contact with the measured skin.A square-wave voltage at a single frequency was applied to the electrodes and the corresponding response current was measured to get the equivalent impedance of human skin.Since it's easy to generate and control a square-wave signal by digital electric circuits,this method is suitable to be used in the portable application.The experimental results indicate that good repeatability and satisfied accuracy can be obtained by this method.

TRANSIENT-STATE RESPONSE OF WAVE PROPAGATION IN MAGNETO-ELECTRO-ELASTIC SQUARE COLUMN

这是在在 magneto-electro-elastic 平方列(MEESC ) 学习波浪繁殖的一个继续的工作。基于在我们在 magneto-electro-elastic 平方列的波浪繁殖的不变的反应在 CME 出版了的以前的纸获得的分析散方程，组速度方程和不变的反应， MEESC 的动态行为在这份报纸被学习。无限的列是一个开的系统。当追求方法的宣传波浪被介绍时，在由任意的外部领域使遭到的开的系统的短暂状态的反应被导出。

SQUARE WAVE COHERENT METHOD FOR EXTRACTING IP EFFECT

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Heat, Resolvent and Wave Kernels with Multiple Inverse Square Potential on the Euclidian Space Rⁿ

In this paper, the heat, resolvent and wave kernels associated to the Schr?dinger operator with multi-inverse square potential on the Euclidian space Rn are given in explicit forms.

Influence of the Source Square Size on the Accuracy of Numerical Simulation of Wave Propagation in Half Space

It is well known that the dynamic response of the structure to an earthquake excitation is affected by the interaction with the foundation and the soil.The expansion of informatics and development of the computer capacities has helped the scientists to develop numerical models for approximate solutions of big variety of problems related to SSI(Soil Structure Interaction).Many of those problems involve domain-coupling.In this paper we built numerical model,based on finite differences and we investigate the accuracy of the numerical model depending upon the size of the square domain around the source.We tested eight different square sizes and we analyzed their accuracy regarding to five different wave periods.The results give recommendations for the implementation of the domain-coupling algorithm.

Nonlinear Waves in Two-Dimensional (2D) Square Lattice Frenkel-Kontorova (FK) System

A 2D 平方格子被学习。由使用连续统近似，我们在使遭到到一个外部周期的底层潜力的方形的格子为一个任意的粒子建立了运动的微分方程。系统的准确独居的波浪被作出对有利的裁决特殊情况。我们断定粘合剂力量 f 和上面、更低的层的角度 αbetween 繁殖方向能影响这些波浪。

Determination of ziram in vegetable samples by square wave voltammetry

电气化学的行为和一个挂的水银落下电极上的二甲氨茺酸锌(zinc-dimethyl dithiocarbamate ) 的电极反应机制在 Britton 鈥揜o binson 被调查(由使用周期、方形的波浪 voltammetry (SWV ) 的 B 鈥揜) 缓冲区。把一个 voltammetric 方法基于这些研究因为二甲氨茺酸锌的决心被开发并且适用在合成、刺的蔬菜样品决定二甲氨茺酸锌，令人满意的结果在两个盒子中被获得。

Osteryoung square wave voltammetric determination of lactose in food samples by a derivative procedure

为在由 Osteryoung 方形的波浪 voltammetry (OSWV ) 的食物样品的乳糖的决心的一个方法被开发。它基于在乳糖和水氨之间的亲核的增加反应。乳糖的羰基组能被变成 imido 组，并且这在减小和敏感增加电气化学的活动。为亲核的增加反应的最佳的条件被调查，它在 pH 的 NH4ClNH3 缓冲区被发现那 10.1，在山峰水流之间的线性范围和乳糖的集中是 0.68.4 mg L ? 1，并且察觉限制是 0.44 mg L ? 1。建议方法在食物样品被用于乳糖的决心，令人满意的结果被获得。

A Compact System of Capacitivity Coupled Contactless Conductivity Detection Based on the Square Wave Excitation Signal for Capillary Electrophoresis

This paper reported a compact system of capacitively coupled contactless conductivity detection (C4D) based on the square wave excitation voltage for capillary electrophoresis, and it exhibited excellent sensitivity at the optimal frequency of 198 kHz. The feasibility and sensitivity of this detector was demonstrated by simultaneous detection of thirteen ions including alkali, alkaline earth and heavy metal ions. And the detection limits (S/N 3) were in the range of 0.2-1 μmol/L for Mn2+, K+, Na+, Mg2+, Ca2+, Li+ , Ba2+, and 7-25 μmol/L for Ni2+, Cu2+, Cd2+, Pb2+, Co2+, Zn2+.

An experimental research of fluid piston oscillation in square moon pool under the wave-flow combined conditions

The article studies the oscillation features of the water in the square moon pool under the circumstances of wave-flow combined conditions. Comparing with the results of experiments of the square moon pool, a series of studies reveal that the water piston oscillation phenomenon is quite similar to that of the circular one. Two types of oscillation are exhibited under different incoming wave periods, i.e. self-excited oscillation and forced oscillation. The difference between the circular and square moon pool is that the attack angle makes greater influences on the square one. "Beating phenomenon" is also found in the square moon pool which is not mentioned of the circular one.

二维正方形介质柱Square格子光子晶体的能带研究

利用平面波展开法计算了两种不同介质材料(GaAs,Ge)构建的二维正方形介质柱Square格子光子晶体的能带结构,研究了介质柱旋转角度、填充比及介质折射率对二维光子晶体禁带结构的影响。结果发现,介质柱旋转角度为0°时,完全光子禁带最大;由不同折射率材料构建的该结构光子晶体,在折射率n=2.57时,即有完全光子禁带产生,为实现用较低折射率材料构建完全禁带光子晶体提供了便利;n=4.10时,完全光子禁带达到最大,禁带宽度Δ=0.048(ωa/2πc)。该研究结果为二维光子晶体应用提供了理论依据。

早期高血压弦脉脉象特点及其瞬时波强技术参数特征分析

目的:应用瞬时波强(WI)技术探测早期高血压弦脉患者颈总动脉各参数,分析早期高血压弦脉的脉象特点;提取弦脉脉象判别的特征参数,探讨早期高血压弦脉患者颈总动脉WI参数的特点,以期为弦脉的精准分型及信息解读提供客观依据。方法:选择52例早期原发性高血压弦脉、50例生理性弦脉、50例平脉受试者,分析其颈总动脉的WI参数,总结早期高血压弦脉的脉象特点,并运用SIMCA14.1统计软件提取脉象分型的主参数。结果:早期高血压弦脉组与平脉组及生理性弦脉组比较,瞬时加速度波强(W1)、负向波面积(NA)值增高,W1-W2间期降低(均P<0.01);而平脉组与生理性弦脉组W1、NA、W1-W2间期比较,差异均无统计学意义(均P>0.05)。平脉组、生理性弦脉组、早期高血压弦脉组的血管压力应变弹性模量(EP)、脉搏波传导速度(PWV)、血管硬化参数(β)数值均逐渐增高(均P<0.01)。平脉组血管顺应性(AC)高于其他2组(均P<0.01),生理性弦脉组AC高于早期高血压弦脉组(P<0.05)。3组R-W1间期比较差异无统计学意义(P>0.05)。基于主成分分析(PCA)和正交偏最小二乘法判别分析(OPLS-DA),生理性弦脉组与平脉组样本区分明显,表明2组WI各参数比较差异均有统计学意义(均P<0.05),特征性的WI参数[投影重要性(VIP值)>1]为EP、PWV、β、AC,其中贡献率为EP>PWV>β>AC。基于PCA和OPLS-DA,生理性弦脉组与早期高血压弦脉组样本区分明显,表明2组WI各参数差异均有统计学意义(均P<0.05),特征性的WI参数(VIP值>1)为EP、PWV、NA、W1、β,其中贡献率为EP>PWV>NA>W1>β。结论:区分早期高血压弦脉组与生理性弦脉组的WI特征性参数为EP、PWV、β、NA、W1。区分平脉组与生理性弦脉组特征性参数为EP、PWV、β、AC。WI技术可为脉象的精准分型和信息解读提供客观依据,值得进一步推广应用。