Rectifier Configurations Based on Harmonic Injecting and Counteracting Principle

On the basis of detailed analysis of a novel harmonic counteracting method which can be used to effectively compensate the supply line harmonic currents of a passive single phase diode bridge rectifier, this paper presents two simpler single phase diode bridge rectifier configurations and their alternatives which can achieve low supply line current THD(total harmonic distortion) too. Moreover, this paper also proposes a few passive hamonic counteracting networks for multi single phase rectifiers which are connected in parallel.

Research on Open-circuit Fault Tolerant Control of Six-phase Permanent Magnet Synchronous Machine Based on Fifth Harmonic Current Injection

This paper proposes a novel control approach for fault-tolerant control of dual three-phase permanent magnet synchronous motor(PMSM) under one-phase open-circuit fault.A modified six-phase static coordinate transformation matrix and an extended rotating coordinate transformation matrix are investigated considering the influence of the fifth harmonic space on fault-tolerant control. These mathematical models are further analyzed in the fundamental space and the fifth harmonic space after the fault and to eliminate the coupling between the d-q axis voltage equation in the fundamental wave space and the d-q axis voltage equation in the fifth harmonic space, a secondary rotation coordinate transformation matrix is proposed. To achieve the purpose of reducing torque ripple, the fault-tolerant control method proposed in this paper not only takes the minimum copper loss as the constraint condition, but also injects the fifth harmonic current. The experimental result of current and torque is used to verify the accuracy of fault-tolerant control.

Non-Invasive Second Harmonic Generation (SHG) in Macroscopy (MacroSHG) as Bio-Diagnosis to Image Collagen Network Organization in Extracellular Matrix

In this work, we have considered a new multimodality imaging for macroscopy based on Second Harmonic Generation (SHG) method to monitor invasivelessly the matrix collagen. As the triple helicoidally structure of collagen molecules appearing as not centrosymetric, very organized and spatially oriented, collagen fibrils give rise to a very strong SHG signal and can be imaged without any exogenous dye. To integrate a multidimensional scale with a large field of view (non-sliced samples), we have adapted and validated an instrumental coupling between a two photon excitation laser and a macroscope to collect cartography of SHG signal. We introduced an index (F-SHG) based on decay time response measured by TCSPC for respectively Fluorescence (F) and Second Harmonic Generation (SHG) values. For various sample where protein collagen is the major component of extracellular matrix (vessel, skin, carotide vessel, rat femoral head cartilage, mouse tumor, human wharton’s jelly and rat tendon) or not (nacre), we compared the index distribution obtained with MacroSHG. In this work, we showed for the first time that multiscale large field imaging (Macroscopy) combined to Multimodality approaches (SHG-TCSPC) could be an innovative and non-invasive technique to detect and identify some biological interest molecules (collagen) in biomedical topics.

A Harmonic Disturbance Suppression Method For Frequency Time-variable Systems

为抑制谐波扰动对控制系统的影响，对频率时变的谐波扰动进行分析，提出两种针对频率时变的谐波扰动的抑制方法：线性反馈方法与基于非线性干扰观测器的方法。线性反馈方法依据于线性矩阵不等式理论，将频率变化的谐波扰动分解为频率固定的谐波扰动与非线性不确定项，采用一般的干扰观测方法对固定频率扰动进行观测，并采用线性反馈方法对非线性不确定项进行抑制。基于非线性干扰观测器的方法直接对谐波扰动进行观测，并采用鲁棒控制器进行干扰补偿。采用李亚普诺夫理论来验证扰动抑制方法的稳定性。将两种扰动抑制方法应用于磁悬浮飞轮电机控制系统，通过仿真与实验结果表明，两种方法具有很好的扰动抑制能力。基于非线性干扰观测器的扰动抑制方法依据扰动的特性设计，具有更好的动态、稳态特性与鲁棒性。

Effects of Shenqi Fuzheng Injection (参芪扶正注射液) on Changes of Matrix Metal loproteinases in Patients with Acute Myocardial Infarction

Objective: To investigate the effects of Shenqi Fuzheng injection (参芪扶正注射液, SQFZI) on ventricular remodeling (VR) after acute myocardial infarction (AMI). Methods: Sixty patients with AMI were randomly divided into two groups and received conventional therapy and conventional therapy plus SQFZI separately. Matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-9 (TIMP-9) in plasma was measured on the 1st and 14th days after AMI. Results: MMP-9 and MMP-9/TIMP-9 were increased after AMI, after 2-week treatment, the level of MMP-9 and MMP-9/TIMP-9 decreased more significantly in SQFZI group than that in the conventional group (P<0. 05). Conclusion: Early treatment with SQFZI after AMI could reduce the level of MMPs and the production of collagen. It may be useful for the prevention of VR and heart failure after AMI.

删边操作下图的Harmonic能量

设G是一个n阶连通图,H(G)是图G的Harmonic矩阵,图G的Harmonic能量定义为矩阵H(G)的所有特征值的绝对值之和。设e=xy是图G的一条边,G-e表示从图G中删除边e=xy得到的图,d_(x)表示顶点x的度。本文讨论了当删除一条非悬挂边e=xy且N_(G)(x)∩N_(G)(y)=■时,连通图G的Harmonic能量的变化。当d_(x),d_(y)≥d时,Harmonic能量变化的上界为2/d√1+16(d-1)/(d+1)^(2);当d_(x),d_(y)≥2时,Harmonic能量变化的上界为5/3。

Disorder Effect on the Transmission of Second Harmonic Waves in One-Dimensional Periodically Poled LiTaO₃

One of the methods for calculating electromagnetic wave dispersion in multi-layer structures is the transfer matrix method. In this paper, we use the transfer matrix method for second harmonic generation in a nonlinear multilayer structure. The nonlinear photonic crystals investigated in this paper are as one-dimensional multi-layered structures including ferroelectric materials such as LiTaO3. Our goal is to investigate the effect of the disorder on the transmission spectrum of electromagnetic waves. Our results showed that positional disorder has different effects on the transmitting band and the gap band. The disorder in the transmitting band reduces the transmission coefficient of the waves and increases the transmission coefficient of the waves in the gap band. Such work has not yet been done on nonlinear photonic crystals producing the second harmonic.

A SINGLE-CAVITY MULTIPLE-DEVICE HARMONIC OSCILLATOR AT W-BAND

The equivalent circuit of single-cavity multiple-device fundamentaloscillator(SCMDFO)and that of single-device harmonic oscillator(SDHO)proposed byK.Kurokawa and K.Solbach,respectively,are extended and applied to a single-cavitymultiple-device harmonic oscillator(SCMDHO).By means of describing the functions ofnonlinearity of Gunn diodes,the performances of the SCMDHO are analyzed.It is foundthat the voltage amplitudes are similar to those of SDHO,and the ratio of maximum pow-er of harmonic to that of fundamental is identical to that in SDHO when the devices havesame parameters.The harmonic injection locking behavior is also investigated.The injec-tion locking range is greater than that of SDHO if locking gain remains constant.A2-Gunn diode harmonic oscillator was designed.It delivers 30mW output power at103GHz.The mechanical tuning range is 4.15GHz when the output power remains morethan 10mW.The desired operation mode is stable.

A multiscale Galerkin method for the hypersingular integral equation reduced by the harmonic equation

The aim of this paper is to investigate the numerical solution of the hypersingular integral equation reduced by the harmonic equation. First, we transform the hypersingular integral equation into 2π-periodic hypersingular integral equation with the map x=cot（θ/2）. Second, we initiate the study of the multiscale Galerkin method for the 2π-periodic hypersingular integral equation. The trigonometric wavelets are used as trial functions. Consequently, the 2j＋1 × 2j＋1 stiffness matrix Kj can be partitioned j×j block matrices. Furthermore, these block matrices are zeros except main diagonal block matrices. These main diagonal block matrices are symmetrical and circulant matrices, and hence the solution of the associated linear algebraic system can be solved with the fast Fourier transform and the inverse fast Fourier transform instead of the inverse matrix. Finally, we provide several numerical examples to demonstrate our method has good accuracy even though the exact solutions are multi-peak and almost singular.

Lindblad Equation for Harmonic Oscillator: Uncertainty Relation Depending on Temperature

Specific nonequilibrium states of the quantum harmonic oscillator described by the Lindblad equation have been hereby suggested. This equation makes it possible to determine time-varying effects produced by statistical operator or statistical matrix. Thus, respective representation-varied equilibrium statistical matrixes have been found. Specific mean value equations have been found and their equilibrium solutions have been obtained.

High-Order Harmonic Generation in the Ionization Process

Based on the nonperturbative quantum electrodynamics scattering theory for multiphoton ionization developed recently,high-order harmonic generated in the ionization process is discussed.The influence of the Coulomb potential is treated as a perturbation in the expansion of the transition matrix.It is deduced that the harmonic photons are emitted in the resonant process during ionization and the width of the harmonic peaks is just the ionization rate of the atom.

与Time-harmonic Maxwell方程有关的Cauchy型积分算子的性质

首先介绍了与N算子有关的Cauchy型积分算子,并证明了以下三种情况下的Holder连续性:两点在边界上;一点在边界上,另一个在区域内(在区域外);两点在区域内(在区域外).接下来介绍了与Time-harmonic Maxwell方程有关的Cauchy型积分算子,研究了它与N矩阵算子有关的Cauchy型积分算子的关系.最后利用上述关系,给出了与Time-harmonic Maxwell方程有关的Cauchy型积分算子在上述三种情况下的Holder连续性.

Spectral shift of solid high-order harmonics from different channels in a combined laser field

We investigate theoretically the spectral shift of the high-order harmonic generation(HHG)in ZnO driven by a combined laser field by solving the two-band semiconductor Bloch equations(SBEs)in the velocity gauge.The combined laser field is synthesized by a fundamental laser pulse and its seventh-frequency laser pulse.When the seventh-frequency laser pulse is added to the rising or falling parts of the fundamental laser field,we find that the spectral blueshift or redshift appears,which is due to the unequal contribution of the rising and falling parts in the fundamental laser field to the harmonics.By analyzing the time-dependent conduction band population in k space,we found that,in addition to the tunneling ionization channel,there is also the resonant electron injection channels which is induced by the seventh-frequency laser pulse.The harmonics generated by the different channels show the spectral redshift or the spectral blueshift,respectively.Through analyzing the k-integrated transient conduction band population of the electrons from different channels,we found that if there is a certain delay in the process of the electron excitation,it will lead to the delay in the harmonic emission,which results in the spectral redshift of the harmonics.

Wear resistance of surface metal matrix composite produced by gas tungsten arc melt injection of Cr3C2 -NiCr particles into low carbon steel

Cr3 C2-NiCr particles were injected into the melted surface of Q235 low carbon steel to make a surface metal matrix composite （MMC） layer by gas tungsten are melt injection （GTAMI） process. Hardness of the surface MMC layer was tested. Wear resistance of the surface MMC was investigated with a ball-on-disk dry sliding setup. Microstrnetures of the surface MMC layer and morphology of the worn surfaces were investigated with scanning electron microscopy （SEM）. The results showed that the hardness of the MMC was as high as 1 960. 7 HV. Wear loss of the upper part of the MMC layer is onlyO. 8% of that of the substrate under the dry sliding condition given. Wear loss of the bottom part is 2. 5 % of that of the substrate.

Power System Harmonics Study for Unbalanced Microgrid System with PV Sources and Nonlinear Loads

Harmonics distortion is a crucial problem in microgrid. Harmonic sources can be categorized as two main factors: renewable energy integration and nonlinear loads. Both factors are investigated in this paper. For renewbale energy, photovoltaic (PV) power is one of the most effective solutions for energy crisis and it is showing great potential for serving customers in microgrid. A three- phase PV source model is establised and integrated at different locations in order to observe the impact of harmonics on a microgrid and power quality (PQ). A composite load is modeled using Crossed Frequency Admittance Matrix theory. A practicdal microgrid loacated at GA, USA is used as a study system. The microgrid, PV model and nonlinear load model are simulated in MATLAB/ Simulink environment. The results show the impact of installing PV sources at two types of locations considering linear and composite nonlinear loads. In addition, three PQ indices are discussed to show the numerical impacts with various perspectives.

研磨处理可注射牙髓细胞外基质促进牙髓再生

背景:可注射细胞外基质材料用于牙髓组织再生时,首先需要经过胃蛋白酶消化,再与其他基质成分如水凝胶结合使用,而这也意味着天然细胞外基质材料所保留的微环境遭到破坏。目的:探讨研磨处理条件下制备的可注射牙髓细胞外基质材料用于牙髓组织再生的效果。方法:(1)将获取的猪牙来源牙髓组织经过脱细胞处理后制备成牙髓脱细胞基质材料,经过液氮冷冻、高速研磨处理后,制备成可注射牙髓细胞外基质材料,比较可注射牙髓细胞外基质材料和天然牙髓细胞外基质在细胞黏附效率和微结构方面的差异,免疫组化分析可注射牙髓细胞外基质中的细胞外基质蛋白质成分;(2)将接种有牙髓干细胞的可注射牙髓细胞外基质材料注入到牙本质基质材料构建的牙髓腔中,植入裸鼠皮下1,3,5周后取材,观察可注射牙髓细胞外基质材料的体内改建速率及其在裸鼠皮下的异位牙髓组织再生能力。结果与结论:(1)与天然牙髓细胞外基质相比,可注射牙髓细胞外基质材料显著提高了细胞黏附率,并保留了与天然牙髓细胞外基质相似的多孔胶原结构;(2)与天然牙髓细胞外基质相比,免疫组化染色显示可注射牙髓细胞外基质材料中层粘连蛋白、Ⅰ型胶原蛋白和整合素β1的表达没有显著变化,而纤连蛋白的表达显著下降;(3)体内实验显示,可注射牙髓细胞外基质材料具有优异的成血管能力,并促进了牙髓样组织的形成。结果表明,研磨处理的可注射牙髓细胞外基质材料可促进牙髓再生。

Overview of Torque Ripple Minimization Methods for Permanent Magnet Synchronous Motors Based on Harmonic Injection

Permanent magnet synchronous motors(PMSMs)are widely used because of their high power/torque density and high efficiency,particularly in applications with strict requirements for arrangement space or weight,such as in the electric vehicle(EV)and aerospace fields.Recently,the PMSM torque ripple problem has received increasing interest because PMSM drive requirements continuously improve.For applications with complex transmission and a wide speed range,torque ripple can easily cause system resonance,which deteriorates the driving performance.The research status and latest progress in the minimization of PMSM torque ripple based on harmonic injection are discussed.First,the causes of PMSM torque ripple are analyzed.Subsequently,the research status of the PMSM analytical model is introduced,and multiple current harmonic control and optimization methods are described in detail.Finally,future development trends in this field are analyzed.

Pretreatment with Danhong injection protects the brain against ischemia-reperfusion injury

Danhong injection （DHI）, a Chinese Materia Medica standardized product extracted from Radix Salviae miltiorrhizae and Flos Carthami tinctorii, is widely used in China for treating acute isch-emic stroke. In the present study, we explored the neuroprotective efficacy of DHI in a rat model of temporary middle cerebral artery ocdusion, and evaluated the potential mechanisms under-lying its effects. Pretreatment with DHI （0.9 and 1.8 mL/kg） resulted in a significantly smaller infarct volume and better neurological scores than pretreatment with saline. Furthermore, DHI significantly reduced the permeability of the blood-brain barrier, increased occludin protein expression and decreased neutrophil infiltration, as well as profoundly suppressing the upreg-ulation of matrix metallopeptidase-9 expression seen in rats that had received vehicle. Matrix metallopeptidase-2 expression was not affected by ischemia or DHI. Moreover, DHI （1.8 mL/kg） administered 3 hours after the onset of ischemia also improved neurological scores and reduced infarct size. Our results indicate that the neuroprotective efficacy of DHI in a rat model of cerebral ischemia-reperfusion injury is mediated by a protective effect on the blood-brain barrier and the reversal of neutrophil infiltration.

Danhong injection A modulator for Golgi structural stability after cerebral ischemiareperfusion injury

The cerebral ischemia-reperfusion model was established using the suture occlusion method, and rats were intraperitoneally given 8 mL/kg Danhong injection once a day prior to model establishment Rat brain tissues were harvested at 6, 24, 48, 72 hours after reperfusion. Immunohistochemical staining showed that transforming growth factor-J31 expression increased, while Golgi matrix protein GM130 expression decreased after cerebral ischemia-reperfusion. Danhong injection was shown to significantly up-regulate the expression of transforming growth factor-131 and GM130, and expres- sion levels peaked at 7 days after reperfusion. At 7 days after cerebral ischemia-reperfusion, Golgi morphology was damaged in untreated rats, while Golgi morphology breakage was not observed after intervention with Danhong injection. These experimental findings indicate that Danhong injec- tion can up-regulate the expression of transforming growth factor-131 and GM130, and maintain Golgi stability, thus playing a neuroprotective role in rats after cerebral ischemia-reperfusion.

考虑光伏不确定性的配电网谐波监测优化配置方法

大规模分布式光伏接入的配电网在运行过程中易产生大量谐波,严重影响电能质量,亟需实现谐波全局可观,为其治理提供数据基础。因此,提出了一种考虑光伏不确定性的谐波监测点优化配置方法。该方法提出了节点综合谐波敏感因子评估配电网节点受谐波影响的程度,从而对节点进行权重划分;进一步地,考虑光照强度和负荷随时间变化的特点,为保证系统在不同时间段内产生的谐波均能被观测到,在谐波潮流计算的基础上,提出了谐波可观测矩阵;基于上述2个评价指标,建立了考虑节点谐波敏感因子的谐波监测优化配置模型,并采用非支配排序遗传算法求解得到了谐波监测点配置方案。在IEEE 33节点配电系统上仿真验证所提方法的有效性,并将所提方法与已有方法进行了对比分析,验证了所提方法的优越性。