An end-to-end denoising autoencoder-based deep neural network approach for fault diagnosis of analog circuit

Analog Integrated Circuits and Signal Processing - Fault diagnosis of analog circuit is critical to improve safety and reliability in electrical systems and reduce losses. Traditional fault...     

纳米SnO_2固体的相变内耗和模量

系统测量了不同颗粒尺度纳米 SnO_2固体的内耗和模量,发现60℃附近存在一个内耗峰,对应的模量出现异常.烧结温度升高,峰高变化不明显,模量异常减弱.当烧结温度高于400℃时,模量曲线在-15℃附近出现异常,这种模量异常随烧结温度升高而加强,对应的内耗曲线出现一小峰.初步认为,60℃附近内耗峰和模量异常与纳米固体中的结构再有序有关,而-15℃处的模量异常为结构相变引起.     

Simulation Method of Dynamic Characteristics of Turbine Flow Sensor

Computational Fluid Dynamics (CFD) simulation is one of the important methods to study the performance and in-fluencing factors of turbine flow sensors. According to the working characteristics of the turbine flow sensor, the passive simulation method based on the six degrees of freedom (6-DOF) model and dynamic mesh is proposed in this paper. The reliability of the simulation method is verified by steady-state experiments and unsteady-state experiments. The results show that the trend of meter factor with flow rate acquired from the simulation is close to the experimental results, and the deviation between the simulation result and the experiment result is low with a maximum deviation of 2.88%. In the unsteady simulation study, the impeller speed changes with the inlet velocity of the turbine flow sensor, which has a good follow-up. The passive simulation method can be used to predict the dynamic performance of the turbine flow sensor.     

CHARACTERISTICS OF INTERNAL FRICTION AND MODULUS ASSOCIATED WITH NON-EQUILIBRIUM DIFFUSION-TYPE PHASE TRANSFORMATION IN EUTECTOID Al-Zn ALLOY

The characteristics of the low frequency internal friction and the modulus effect associatedwith the non-equilibrium spinodal pretransformation and the following discontinuous trans-formation was investigated in an as-quenched eutectiod Al-Zn alloy.It was observed that theloss of the stability in the lattice,which corresponded to the large-amplitude long-wavelengthstatic concentration wave in the non-equilibrium spinodal pretransformation,did not induceany effect of localized soft modulus.Although there are two aging internal friction peaks inphase transformation which correspond to the appearance and disappearance of the coherencyin spinodal pretransformation and the maximum of the interface area in the discontinuoustransformation respectively,the effect of localized soft modulus did not take place yet.     

滚压成形力的数值计算与模拟

滚压成形技术在工程中的应用越来越广泛.但是到目前为止,滚压成型方面的理论还不完善,有些计算公式还有待验证.本文对板材进行U型成形时的成形力与成形角和板厚之间的关系进行了模拟数值计算和现场测量,并与经验公式的计算结果进行了比较,存在有较大的差异,从而说明经验计算公式有待进一步修正.     

Ag—Cu纳米合金的微观结构

利用高分辨电镜（ＨＲＥＭ）对气相凝聚法制备的Ａｇ１－ｘＣｕｘ（０．０５≤ｘ≤０．４０）纳米合金样品中的微观结构进行了研究．结果表明，在所有合金样品中，都没有观察到明显的界面亚稳相的形成，且晶界具有有序的原子结构样品中两组元的等轴纳米晶粒分布均匀，但随着Ｃｕ含量的增加，Ｃｕ颗粒出现明显的偏聚和粗化；与稳定相相比，富Ａｇ和富Ｃｕ相的点阵常数没有发生显著的变化．     

大宁河补水工程环境地质条件与布置方案研究(Ⅱ)

针对丹江口水库远期补水需要,对大宁河补水工程的环境工程地质条件进行了全面研究,全面论述了东西线4个比选方案。研究认为：各方案深埋长隧洞为工程难点,但就国内外已建工程经验而言,暂未发现在经济条件许可的前提下存在不可克服的技术问题。对4个组合方案环境工程地质条件、重要非地质因素进行了比选研究,认为：西线优势方案“西线剪刀峡（檀木-茅草坡）方案”在二级泵站站址、控制性穿岭隧洞长度及其可实现最短施工长度、隧洞埋深、不稳定类岩体长度等方面优势明显;就重要非地质因素而言,该方案在抽水蓄能效益、带动当地经济发展、投资集约度与灵活度等方面优势明显,在调水保证度这一核心任务方面,西线具有突出优越性。     

Deterministic Polymorphic Engineering of MoTe2 for Photonic and Optoelectronic Applications

Developing selective and coherent polymorphic crystals at the nanoscale offers a novel strategy for designing integrated architectures for photonic and optoelectronic applications such as metasurfaces, optical gratings, photodetectors, and image sensors. Here, a direct optical writing approach is demonstrated to deterministically create polymorphic 2D materials by locally inducing metallic 1T′-MoTe₂ on the semiconducting 2H-MoTe₂ host layer. In the polymorphic-engineered MoTe₂, 2H- and 1T′- crystalline phases exhibit strong optical contrast from near-infrared to telecom-band ranges (1–1.5 µm), due to the change in the band structure and increase in surface roughness. Sevenfold enhancement of third harmonic generation intensity is realized with conversion efficiency (susceptibility) of ≈1.7 × 10⁻⁷ (1.1 × 10⁻¹⁹ m² V⁻²) and ≈1.7 × 10⁻⁸ (0.3 × 10⁻¹⁹ m² V⁻²) for 1T′ and 2H-MoTe₂, respectively at telecom-band ultrafast pump laser. Lastly, based on polymorphic engineering on MoTe₂, a Schottky photodiode with a high photoresponsivity of 90 AW⁻¹ is demonstrated. This study proposes facile polymorphic engineered structures that will greatly benefit realizing integrated photonics and optoelectronic circuits.     

新型均速管涡街流量传感器的测量特性研究

本文提出了新型均速管涡街流量传感器,实现差压与频率信号的双参数测量,并根据涡街信号的不同采集方式分为压 电式和差压式两种类型。 对两种一体化流量传感器的结构、原理以及信号采集方式进行了设计和阐述,并对其测量特性进行对 比分析。 结果表明,采用差压式流量传感器与经验小波变换(EWT)相结合,能将量程比由 10:1 拓宽至 140:1。 单相气最大测 量误差绝对值由 1. 46%减小至 0. 49%,重复性由 0. 17%降至 0. 05%,水流量最大测量误差绝对值也实现了从 1. 00%下降至 0. 49%,重复性低于 0. 07%。 与压电式流量传感器相比,差压式均速管涡街流量传感器在测量精度及测量范围中具有一定的应 用优势,为湿蒸汽测量提供了一种新思路。     

基于统计方法的中文姓名识别

本文介绍一个中文姓名的自动识别系统,该系统使用从姓名样本库和真实文本语料库中得到的大量统计数据,以提高系统识别性能。我们从1994年人民日报中随机抽取100篇文章作为测试样本,实验结果表明,准确率和召回率可同时达到90%以上。