A deep trench super-junction LDMOS with double charge compensation layer

A deep trench super-junction LDMOS with double charge compensation layer(DC DT SJ LDMOS)is proposed in this paper.Due to the capacitance effect of the deep trench which is known as silicon-insulator-silicon(SIS)capacitance,the charge balance in the super-junction region of the conventional deep trench SJ LDMOS(Con.DT SJ LDMOS)device will be broken,resulting in breakdown voltage(BV)of the device drops.DC DT SJ LDMOS solves the SIS capacitance effect by adding a vertical variable doped charge compensation layer and a triangular charge compensation layer inside the Con.DT SJ LDMOS device.Therefore,the drift region reaches an ideal charge balance state again.The electric field is optimized by double charge compensation and gate field plate so that the breakdown voltage of the proposed device is improved sharply,meanwhile the enlarged on-current region reduces its specific on-resistance.The simulation results show that compared with the Con.DT SJ LD-MOS,the BV of the DC DT SJ LDMOS has been increased from 549.5 to 705.5 V,and the R_(on,sp) decreased to 23.7 mΩ·cm^(2).

Charge compensation and capacity fading in LiCoO2 at high voltage investigated by soft x-ray absorption spectroscopy

In order to obtain an in-depth insight into the mechanism of charge compensation and capacity fading in LiCoO2, the evolution of electronic structure of LiCoO2 at different cutoff voltages and after different cycles are studied by soft x-ray absorption spectroscopy in total electron（TEY） and fluorescence（TFY） detection modes, which provide surface and bulk information, respectively. The spectra of Co L2,3-edge indicate that Co contributes to charge compensation below 4.4 V.Combining with the spectra of O K-edge, it manifests that only O contributes to electron compensation above 4.4 V with the formation of local O 2 p holes both on the surface and in the bulk, where the surficial O evolves more remarkably. The evolution of the O 2 p holes gives an explanation to the origin of O2^-or even O2. A comparison between the TEY and TFY of O K-edge spectra of LiCoO2 cycled in a range from 3 V to 4.6 V indicates both the structural change in the bulk and aggregation of lithium salts on the electrode surface are responsible for the capacity fading. However, the latter is found to play a more important role after many cycles.

Carbon decorated Li_(3)V_(2)(PO_(4))_(3) for high-rate lithium-ion batteries:Electrochemical performance and charge compensation mechanism

Fast charging and high-power delivering batteries are highly demanded in mobile electronics,electric vehicles and grid energy storage,but there are full of challenges.The star-material Li_(3)V_(2)(PO_(4))_(3) is demonstrated as a promising high-rate cathode material meeting the above requirements.Herein,we report the carbon decorated Li_(3)V_(2)(PO_(4))_(3) (LVP/C) cathode prepared via a facile method,which displays a remarkable high-rate capability and long-term cycling performance.Briefly,the prepared LVP/C delivers a high discharge capacity of 122 mAh g^(-1)(-93% of the theoretical capacity) at a high rate up to 20 C and a superior capacity retention of 87.1% after 1000 cycles.Importantly,by applying a combination of X-ray absorption spectroscopy and full-range mapping of resonant inelastic X-ray scattering,we clearly elucidate the structural and chemical evolutions of LVP upon various potentials and cycle numbers.We show unambiguous spectroscopic evidences that the evolution of the hybridization strength between V and O in LVP/C as a consequence of lithiation/delithiation is highly reversible both in the bulk and on the surface during the discharge-charge processes even over extended cycles,which should be responsible for the remarkable electrochemical performance of LVP/C.Our present study provides not only an effective synthesis strategy but also deeper insights into the surface and bulk electrochemical reaction mechanism of LVP,which should be beneficial for the further design of high-performance LVP electrode materials.

Optically controlled SiCGe/SiC heterojunction transistor with charge-compensation layer

A novel optically controlled SiCGe/SiC heterojunction transistor with charge-compensation technique has been simulated by using commercial simulator. This paper discusses the electric field distribution, spectral response and transient response of the device. Due to utilizing p-SiCGe charge-compensation layer, the responsivity increases nearly two times and breakdown voltage increases 33%. The switching characteristic illustrates that the device is latch-free and its fall time is much longer than the rise time. With an increase of the light power density and wavelength, the rise time and fall time will become shorter and longer, respectively. In terms of carrier lifetime, a compromise should be made between the responsivity and switching speed, the ratio of them reaches maximum value when the minority carrier lifetime equals 90 ns.

Modeling of high permittivity insulator structure with interface charge by charge compensation

An analytical model of the power metal–oxide–semiconductor field-effect transistor(MOSFET)with high permittivity insulator structure(HKMOS)with interface charge is established based on superposition and developed for optimization by charge compensation.In light of charge compensation,the disturbance aroused by interface charge is efficiently compromised by introducing extra charge for maximizing breakdown voltage(BV)and minimizing specific ON-resistance(R_(on,sp)).From this optimization method,it is very efficient to obtain the design parameters to overcome the difficulty in implementing the R_(on,sp)–BV trade-off for quick design.The analytical results prove that in the HKMOS with positive or negative interface charge at a given length of drift region,the extraction of the parameters is qualitatively and quantitatively optimized for trading off BV and Ron,sp with JFET effect taken into account.

Unveiling the mechanism of charge compensation in Li_(2)Ru_(x)Mn_(1-x)O_(3)by tracking atomic structural evolution

The relationship between the structural evolution and redox of Li-rich transition-metal layered oxides(LLOs)cathodes remains ambiguous,obstructing the development of high-performance lithium-ion(Li^(+))battery.Herein,the coherent effects of local atomic and electronic structure in Li_(2)Ru_(x)Mn_(1-x)O_(3)(LRMO)with a wide voltage window(1.3–4.8 V)is identified by in situ X-ray absorption fine spectroscopy(XAFS)and chemometrics.We not only skillfully separated the redox active structures to track the electrochemical path,but also visualized the coupling mechanism between the evolution of Ru-Ru dimer and the(de)excitation of cations and anions.Furthermore,introducing manganese triggers the“heterogeneity”of coordination environment and electronic structure between Ru and Mn after discharge to 3 V.The change of thermodynamic and kinetic paths affects the relithiation,and further leads to the hysteresis of the anion activation structure relaxation of Li_(2)Ru_(0.4)Mn_(0.6)O_(3)relative to Li_(2)RuO_(3)(LRO).Additionally,it is demonstrated that the high charge cut-off voltage restrains the relaxation of anionic active structure in LRO from a new perspective through comparative experiments.Our work associates the evolution of atomic structure with charge compensation and negative electrochemical reactions such as voltage hysteresis(VH)and capacity attenuation,deepening the understanding electrochemical reaction mechanism of LLOs during the first cycle and providing a theoretical support for the further design and synthesis of high-efficiency cathodes.

Spatial charge and compensation method in a whirler

Based on particle-in-cell simulation, we studied the motions of ions and electrons. The results have shown that electrons are bounded by a magnetic field and only a small number of electrons can pass through the whirler channel. The plasma becomes non-neutral when it is emitted from the whirler, and the spatial charge leads to a beam divergence, which is unfavorable for mass separation. In order to compensate the spatial charge, a cathode is designed to transmit electrons and the quasi-neutral plasma beam. Experiment results have demonstrated that the auxiliary cathode can obviously improve the compensation degree of the spatial charge.

ONLINE GRINDING WHEEL WEAR COMPENSATION BY IMAGE BASED MEASURING TECHNIQUES

Automatic compensation of grinding wheel wear in dry grinding is accomplished by an image based online measurement method. A kind of PC-based charge-coupled device image recognition system is schemed out, which detects the topography changes of the grinding wheel surface. Profile data, which corresponds to the wear and the topography, is measured by using a digital image processing method. The grinding wheel wear is evalualed by analyzing the position deviation of the grinding wheel edge. The online wear compensation is achieved according to the measure results. The precise detection and automatic compensation system is integrated into an open structure CNC curve grinding machine. A practical application is carried out to fulfil the precision curve grinding. The experimental results confirm the benefits of the proposed techniques, and the online detection accuracy is less than 5 um. The grinding machine provides higher precision according to the in-process grinding wheel error compensation.

白光LED用ZnMoO_4∶Tb^(3+),K^+发光材料的制备及发光特性

采用高温固相法合成了Zn0.85Tb0.15MoO4绿色荧光粉,利用XRD和荧光光谱仪对样品进行了测试表征。XRD测试结果表明,在800°C温度下烧结能形成ZnMoO4纯相。激发光谱由MoO42-的电荷迁移宽带(CT)和Tb3+离子特征激发峰组成;研究发现,掺杂了K+离子后电荷迁移带峰位位置向短波方向移动;分析了碱土金属离子K+作为电荷补偿剂对样品发光性能的影响,发现加入电荷补偿剂可大大提高样品的发光强度。该荧光粉的发射光谱光由位于487 nm,543 nm,584 nm,620 nm处的四组发射峰组成,分别对应Tb3+的5D4-7F6(487 nm),5D4-7F5(543 nm),5D4-7F4(584 nm)和5D4-7F3(620 nm)能级跃迁,而5D4-7F5(543 nm)的跃迁发射最强。

A Novel Method to Compensate the Sigma-Delta Shaped Noise for Wide Band Fractional-N Frequency Synthesizers

A novel method to partially compensate sigma-delta shaped noise is proposed. By injecting the compensation current into the passive loop filter during the delay time of the phase frequency detector（PFD）,a maximum reduction of the phase noise by about 16dB can be achieved. Compared to other compensation methods,the technique proposed here is relatively simple and easy to implement. Key building blocks for realizing the noise cancellation,including the delay variable PFD and compensation current source, are specially designed. Both the behavior level and circuit level simulation results are presented.

Luminescence enhancement of CaMoO_(4):Eu^(3+) phosphor by charge compensation using microwave sintering method

CaMoO_(4):Eu^(3+)and CaMoO_(4):Eu^(3+),A+(A=Li,Na,K)phosphors for light-emitting diode(LED)applications have been prepared by microwave sintering method(MSM),and their structure and luminescence properties are investigated.The influences of microwave reaction time and concentration of different kinds of charge compensation A+and Eu^(3+)on luminescence have also been discussed.The samples emit a red luminescence at 615 nm attributed to the^(5)D0→^(7)F2 transition of Eu^(3+)under 464 nm excitation.It is observed that adding charge compensation A+in the sample synthesis increases luminescence intensity.The optimized sample made with 32 mol%Li+and 32 mol%Eu^(3+)has an enhancement factor of 4 in photoluminescence compared to the sample made without charge compensation.The CIE(Commission Internationale de l'Eclairage)coordinates of Ca0.36MoO_(4):0.32Eu^(3+),0.32Li+are x=0.661 and y=0.339,which indicate that the obtained phosphor can be a promising red color candidate for white LED fabrications.

Determination of total ginsenosides in ginseng extracts using charged aerosol detection with post-column compensation of the gradient

AIM: Variation in structure-related components in plant products prompted the trend to establish methods, using multiple or total analog analysis, for their effective quality control. However, the general use of routine quality control is restricted by the limited availability of reference substances. Using an easily available single marker as a reference standard to determine multiple or total analogs should be a practical option. METHOD: In this study, the Ultra-HPLC method was used for the baseline separation of the main components in ginseng extracts. Using a plant chemical component database, ginsenosides in ginseng extracts were identified by Ultra-HPLC-MS analysis. The charged aerosol detection(CAD) system with post-column compensation of the gradient generates a similar response for identical amounts of different analytes, and thus, the content of each ginsenoside in ginseng extracts was determined by comparing the analyte peak area with the reference standard(determination of total analogs by single marker, DTSM). The total ginsenoside content was determined by the summation of reference standard and other ginsenoside components. RESULTS: The results showed that DTSM approaches were available for the determination of total ginsenosides in a high purity ginseng extract because of the removal of impurities. In contrast, DTSM approaches might be suitable for determination of multiple ginsenosides without interference from impurities in the crude ginseng extract. CONCLUSION: Future practical studies similar to the present study should be conducted to verify that DTSM approaches based on CAD with post-column inverse gradient for uniform response are ideal for the quality control of plant products.

K^+掺杂对CaTiO_3:Eu^(3+)的荧光性能影响

采用静电纺丝法合成K^+作为电荷补偿剂的CaTiO_3∶Eu^(3+)纳米纤维,采用X射线衍射仪、荧光光谱仪对材料的物相和发光性能进行了表征。样品的激发光谱由370~420nm的光谱组成,其中398nm的激发强度最大。发射光谱主要由位于617nm处的主峰(来源于~5D_o-~7F_2能级间的跃迁发射)及在589nm、652nm处的发光峰(分别来源于~5D_o-~7F_1、~5D_o-~7F_3能级间的跃迁发射)构成。掺入K^+有效提高了CaTiO_3∶Eu^(3+)纳米纤维的发光强度,发光强度随着掺杂浓度的增加而增加,掺杂K^+为5%时为浓度淬灭点。

钙钛矿结构荧光材料MZrO_3:Eu^(3+),A(M=Ca^(2+), Ba^(2+);A=Li^+, Na^+, K^+)的制备及其发光性质(英文)

Calcium and barium zirconate powders based upon CaZrO 3:Eu3+ , A and BaZrO 3:Eu3+, A(A=Li+, Na+, K+) were prepared by combustion synthesis method and heating to ~1000 °C to improve crystallinity. The structure and morphology of materials were examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD results showed that CaZrO 3:Eu3+, A and BaZrO 3:Eu3+, A (A=Li+, Na+, K+) perovskites possessed orthorhombic and cubic structures, respectively. The morphologies of all powders were very similar consisting of small, coagulated, cubical particles with narrow size distributions and smooth and regular surfaces. The characteristic luminescences of Eu 3 + ions in CaZrO 3 :Eu3+ , A (A=Li+, Na+, K+) lattices were present with strong emissions at 614 and 625 nm for 5D0 →7F2 transitions with other weaker emissions observed at 575, 592, 655, and 701 nm corresponding to 5D0 → 7Fn transitions (where n=0,1,3,4, respectively). In BaZrO3:Eu3 + both the 5D0 → 7F1and5D0 → 7F2 transitions at 595 and 613 nm were strong. Photoluminescence intensities of CaZrO3:Eu3+samples were higher than those of BaZrO 3:Eu3+lattices. This remarkable increase of photoluminescence intensity (corresponding to 5D0→7Fn transitions) was observed in CaZrO3:Eu3+and BaZrO3:Eu3+ if co-doped with Li + ions. An additional broad band composed of many peaks between 440 to 575 nm was observed in BaZrO3:Eu3+, A samples. The intensity of this band was greatest in Li + co-doped samples and lowest for K + doped samples.

Effects of charge compensation on red emission in CaYAl_3O_7:Eu^(3+) phosphor

Monovalent ions Li＋, Na＋, and K＋, as charge compensators, are introduced into CaYA1307： M （M = Eu3＋, Ce~＋） in this letter. Their crystal phases and photoluminescence properties of different alkali metal ions doped in CaYA1307 are investigated. In addition, the influence of charge compensation ion Li＋ which has a more obvious role in improving luminescence intensity on CaYA1307： Eu3＋ phosphor is intentionally discussed in detail and a possible mechanism of charge compensation is given. The enhancement of red emission centered at 618 nm belonging to Eu3＋ is achieved by adding alkali metal ion Li＋ under 393-nm excitation.

考虑补偿激励的电动汽车多区域优化调度策略

针对充电区域内分布式新能源(DRE)与电动汽车负荷供需不均的问题,提出一种考虑补偿激励的电动汽车多区域优化调度策略,引导电动汽车前往不同充电区域充电,以促进DRE就地消纳.首先,基于需求价格弹性及用户时间焦虑建立电动汽车用户需求电量模型.其次,基于剩余电量可达原则和空闲时间冗余原则将电动汽车划分为可响应和不可响应集群,利用基于后悔理论的充电区域决策模型对可响应集群按区域作进一步划分.最后,建立电动汽车多区域优化调度模型,从最大化充电服务商经济效益及DRE消纳程度两个方面对充电价格进行优化.通过仿真验证证明所提优化策略能够充分考虑时间焦虑和价格弹性对电动汽车用户的影响,充分挖掘用户的响应潜力,在降低DRE消纳偏差量和提高充电服务商经济效益方面具有明显效果.

空间约束下电动汽车无线充电系统磁耦合结构优化

电动汽车无线充电系统在尺寸大小与位置偏移等因素的影响下,会导致系统传输能力下降。为了在空间约束条件下提升系统的输出功率、传输效率及抗偏移能力,针对位置偏移与底盘高度不同的实际情况,在经典D4线圈的基础上分别设计了收发端非对称D4和收发端非对称D4Q双层线圈磁耦合结构,以提高耦合系数和抗偏移能力。在不同方向的偏移和旋转的情况进行仿真测试,表明收发端非对称D4Q双层线圈在出现横向偏移300 mm、纵向偏移400 mm、传输距离230 mm和旋转偏移45°以内具备无线电能传输能力。通过搭建实验平台对偏移进行测试与验证,结果表明,所提出的收发端非对称D4Q磁耦合结构的最大输出功率相对于收发端对称D4磁耦合结构增加约60.34%,最大传输效率增大11%。

建筑电气节能系统的谐振抑制方法研究

文章建立谐振拓扑模型,提出整流电路、逆变电路以及无线电能传输系统线圈的设计方案,并对线圈传输效率进行分析。结果表明,系统整体性能受耦合线圈参数值的影响较大。因此,需要调整品质因数与耦合系数值来提高系统整体性能,通过仿真验证实验电路的可靠性和可行性。

基于卡尔曼滤波算法的电池状态估计

为更好地获得锂离子电池荷电状态SOC(state-of-charge)估计值,选用二阶等效电路模型作为研究对象,针对带有遗忘因子的递推最小二乘法在参数辨识中易受到噪声等环境因素干扰的缺点,提出偏差补偿最小二乘法来实现模型参数的准确辨识,并结合无迹卡尔曼滤波算法对SOC进行估计。针对无迹卡尔曼滤波算法稳定性差等缺点,提出利用权重向量更新滤波算法中的卡尔曼滤波增益。实验结果表明,所提算法估计SOC的总误差可控制在2.7%以内,验证了算法的鲁棒性和有效性。

电动汽车无线充电系统中弯道互感优化研究

针对采用感应耦合电能传输技术的电动汽车无线充电过程中,汽车内部的能量拾取线圈在转弯过程中互感下降问题,提出使用内嵌入圆形线圈进行补偿,并通过遗传算法、理论推导和仿真验证,得到了补偿线圈最优化匝数和统一规格参数。通过搭建COMSOL Multiphysics平台、MATLAB/Simulink平台结合的仿真平台和实物实验平台,实验数据证实:在转弯时采用内嵌圆形线圈进行补偿,优化补偿后互感波动保持在±0.4%左右,由于互感波动的平稳,使得电动汽车能量拾取系统电压优化补偿后波动为3.6%。