RLC串联谐振特性的实验研究

RLC串联谐振电路实验中谐振特性的实验曲线与理论曲线总存在一定的误差,且谐振频率越高时,偏差越大.本文通过实验研究,分析了电感和电容串联总损耗电阻对谐振曲线及Q值的影响,利用实验所测得的电感和电容串联总损耗电阻对谐振曲线及Q值进行修正,发现修正后的理论结果与实验测量数据吻合得较好.     

Corrosion process detection of tinplate in deaerated functional beverage by EIS

The corrosion process of tinplate in deaerated functional beverage was investigated by using electrochemical impedance spectroscopy (EIS) combined with scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) techniques. The results reveal that the uncoated tinplate shows a poor corrosion resistance and the corrosion type is detinning. During the initial stage of immersion, EIS spectrum consisted of two capacitance arcs with obvious time-constant dispersion effect, which was attributed to the two-dimensional and three-dimensional inhomogeneous distribution of the electrode surface. With the increase of immersion time, the capacitance arc of high frequency shrunk and degenerated, due to the corrosion of tin coating. The pore resistance of tin coating and the charger transfer resistance of substrate, which are determined from the electrochemical equivalent circuit, can be used as the indicators of tinplate corrosion process. The decrease of the pore resistance of tin coating indicates that the corrosion degree of tin layer becomes more severe, whereas the decrease of the charger transfer resistance of substrate implies that the corrosion degree of steel substrate also becomes more severe as the immersion time prolongs.     

准确测量整流滤波电路负载电阻的方法

在半波整流电容滤波电路中,由于负载电阻上输出电压的脉动较小,接近于直流电。给负载电阻的测量带来了很大误差,本文介绍了一种方法,可以准确测量电阻的大小,不受脉动大小的影响。可作为一个较好的设计性实验课题。     

Switching Characteristics and Analysis of Resonant Tunneling Diodes

Resonant tunneling diode （RTD） of AlAs/InGaAs/AlAs double barrier-single well structure was designed and fabricated. The devices showed current-voltage characteristics with peak-valley current ratio of 4 ： 1 at room temperature. The scattering parameter of RTD was measured by using an HP8510（C） network analyzer. Equivalent circuit parameters were obtained by curve fitting and optimized. The RTD switching time was estimated using the measured capacitance and average negative differential resistance. The minimum rise time of the sample was estimated to be 21 ps.     

一种新颖的Ⅱ型双极性权电容D／A转换器的设计

在分析通用电容网络D／A转换器的基础上,给出了Ⅱ型电容网络单元及串联电容计算方法,提出了一种全新的Ⅱ型双极性电容输出D／A转换器,该电容网络拥有电容个数少,电容取值方便,在电子技术的应用领域具有重要的理论及应用价值．     

非线性电容RLC串联电路的2次超谐共振分析

以非线性电容RLC串联电路为研究对象,应用多尺度法求得2次超谐共振的幅频响应方程,并且通过数值计算可知,电子元器件的参数变化对振幅值具有影响,幅频响应曲线具有跳跃和滞后现象,即电阻可以抑制振幅值,电源、电容、电感可以增大振幅值。     

变容二极管调频器获得线性调频的条件

导出变容二极管调频器获得线性调频的条件,并讨论其调制灵敏度．     

Cr12MoV钢电火花沉积工艺研究

电火花沉积工艺（ESD）是一种微弧焊工艺,电极材料沉积到基体表面,并于基体呈冶金结合．本文以冷作模具钢Cr12MoV为基体材料,利用电火花沉积对局部区域进行修复．研究了影响沉积层质量和沉积率的工艺参数,其中包括电容、电压和保护气．实验结果显示,虽然随着电容和电压的增大,沉积率提高,但同时也会使沉积层中的微裂纹和孔洞增加．因此,只有合理选择沉积工艺参数,才能达到一定沉积率的同时保证沉积层的质量．     

实验教学中的模拟滤波器参数设计

基于滤波器设计在模拟电子技术实验教学中的基础性重要作用,阐述了滤波器参数归一化表的推导过程,以帮助学生更深层次的理解滤波器的原理与设计方法。通过比较RC双极点滤波器传输函数和归一化之后的传输函数,得到归一化的电阻电容值,进而通过求解归一化计算得出实际电路中的元器件的参数。采用同样的方法可以得出三阶滤波器的参数,将二阶滤波器和三阶滤波器级联就可以得到任意阶的滤波器。实际实验测试证明了此方法的有效性。介绍了计算机辅助设计的方法,帮助实验中的滤波器指标调试,也方便了学生的自主探索学习。针对实验教学学生实际调试中可能出现的问题提出了一些解决对策,给出多种解决问题的思路。     

润滑油抗乳化性能研究创新型实验设计

根据目前润滑油抗乳化性研究最新进展与国家标准,设计了创新研究型的润滑油抗乳化性能研究实验.该实验模拟实际工况条件,改变油水比,设计单次乳化以及多次连续乳化实验,除采用传统的分水率、分水速度、油水外观和界面齐整度以及乳化层厚度等抗乳化性评价指标外,还利用紫外分光光度法测定了水相含油量,利用微量水分全自动测定仪测定了油相含...     

Charge meter: Easy way to measure charge and capacitance some interesting electrostatic experiments

A simple and inexpensive method of building a charge meter is discussed and as an application two experiments are suggested. A charge meter can be used for identification and measurement of charges on dielectric media such as teflon, nylon, silk and rubber balloon obtained by method of friction. Teflon and rubber balloon are found to be negatively charged while silk and nylon are found to be positively charged. A charge meter can also be used to measure capacitance of parallel plate capacitors and hence calculate dielectric constant of the medium between its plates. The values of dielectric constant of transparency plastic sheet and plain paper so obtained are 2.71 ± 0.08 and 4.8 ± 0.29. In the last part, the effective capacitance of a capacitor obtained by placing paper and transparency plastic sheet placed one above the other is shown to be equivalent to a series combination of individual paper and transparency plastic sheet capacitors. These experiments can be pedagogical tools for teaching electrostatics.     

Thin emitter structure improved turn-on characteristics in RSD

The thin emitter structure was introduced into reversely switched dynistor (RSD) to improve its turn-on characteristics. According to the analysis of turn-on condition, thin emitter structure is capable of reducing the extraction action for the triggering plasma layer P1 during turn-on process, and satisfying the requirement that triggering electric charge cannot be exhausted and therefore enables RSD to turn on uniformly. The on-state thin emitter RSD was equivalent to an asymmetric pin diode model. The simulation result shows that the forward voltage drop of RSD falls with the decrease of doping dose in p -emitter in a certain range, and when the doping concentration is extremely low, the decrease of the width of p -emitter can obtain a low forward voltage drop. Thin emitter RSD chips were made by sintering Al on n-Si. The test result shows that their turn-on process is uniform and the voltage drop is 7.5V when the peak conversion current is 5500A.     

植物病害诊断仪的传感机理研究

植物病害诊断仪的使用效果确实可靠。然而对它的传感机理总觉得难以置信。对植物电阻、电势等变化 ,静态实验即可证明。而电容参量只有在动态下才具有可测性 ,因而实验繁难。本文在大量数据基础上以图解方式从 5个方面定性简述了植物具有电容 ,并确证了该仪器电容传感机理的真实性     

半导体功率型LED应用热阻的研究

热阻是功率型LED应用中的一个重要参数。本文简述了LED热阻的概念,对典型的LED应用建立了热阻模型,并研究了热阻的测量原理及测试方法,为LED器件应用设计及其可靠性提供了依据。     

稳压二极管动态电阻的示波器测量法

用示波器的“DC”、“AC”两种输入耦合方式及信号发生器的交、直流输出电压测量稳压二极管的动态电阻并加以推广。     

基于时域卷积与双向GRU神经网络的时序预测模型

随着物联网技术和5G技术的发展,各类智能设备收集的时序数据规模急剧增长,为了利用深度学习技术对大规模时序数据进行预测,提出一种基于深度神经网络的时序预测模型。该模型首先利用时域卷积神经网络层对时序数据进行预处理,然后利用双向GRU神经网络层提取时序数据的前向特征和后向特征,最后对时序数据进行预测。在真实数据集上的实验结果表明,该模型相比传统长短期记忆网络模型,预测准确度提高了近70%,预测速度提高了近10%,可更好地满足对大规模时序数据的预测需求。     

等效表面电荷对斜角造型p-n结表面电场的影响(英文)

<正>The space-charge layer(SCL)and surface depletion area(SDA)model for beveled p-n junction is presented.The surface space-charge density is calculated for depletion case of beveled p-n junction.Based on the finite difference method, the effect of the equivalent surface charge density on the surface depletion area for positively beveled p-n junction is also studied.Thyristors passivated with polyimide(PI)or polyester improved silicon paint(SP)are fabricated to verify the effect of equivalent surface charge on the peripheral surface of beveled p-n junction.The change of leakage current is sensitive to the surface charges.It indicates that the selection of passivation materials is a significant process to ensure the breakdown voltage capability of beveled devices.     

Space Charge Layer Effect in Sulfide Solid Electrolytes in All-Solid-State Batteries: In-situ Characterization and Resolution

All-solid-state lithium batteries (ASSLBs) have advantages of safety and high energy density, and they are expected to become the next generation of energy storage devices. Sulfide-based solid-state electrolytes (SSEs) with high ionic conductivity and low grain boundary resistance exhibit remarkable practical application. However, the space charge layer (SCL) effect and high interfacial resistance caused by a mismatch with the current commercial oxide cathodes restrict the development of sulfide SSEs and ASSLBs. This review summarizes the research progress on the SCL effect of sulfide SSEs and oxide cathodes, including the mechanism and direct evidence from high performance in-situ characterizations, as well as recent progress on the interfacial modification strategies to alleviate the SCL effect. This study provides future direction to stabilize the high performance sulfide-based solid electrolyte/oxide cathode interface for state-of-the-art ASSLBs and future all-SSE storage devices.

     

钢桥面环氧沥青铺装的界面行为

通过引入一个新参数膜劲度,在部分共同作用原理的基础上,建立了描述钢桥面环氧沥青混凝土铺装复合梁在负弯矩作用下的界面行为模型,用以分析钢-环氧沥青混凝土之间的界面滑移与应变.推导了弹性工作状态下复合梁的界面滑移与应变的表达式,编制了数值计算程序并用2根复合梁进行了校核.然后采用该程序分析了界面滑移与应变沿复合梁纵向的分布特征,以及铺装层中的最大拉应力、层间剪应力对材料参数的敏感性.结果表明,界面效应削弱了钢桥面铺装复合梁的整体抗弯刚度;中低温条件下,采用劲度更大的粘结层材料有利于改善沥青铺装层的受力;粘结层的损伤累积将加剧沥青铺装层的破坏.