3D‑Printed Carbon‑Based Conformal Electromagnetic Interference Shielding Module for Integrated Electronics

Electromagnetic interference shielding(EMI SE)modules are the core com-ponent of modern electronics.However,the tra-ditional metal-based SE modules always take up indispensable three-dimensional space inside electronics,posing a major obstacle to the integra-tion of electronics.The innovation of integrating 3D-printed conformal shielding(c-SE)modules with packaging materials onto core electronics offers infinite possibilities to satisfy ideal SE func-tion without occupying additional space.Herein,the 3D printable carbon-based inks with various proportions of graphene and carbon nanotube nanoparticles are well-formulated by manipulating their rheological peculiarity.Accordingly,the free-constructed architectures with arbitrarily-customized structure and multifunctionality are created via 3D printing.In particular,the SE performance of 3D-printed frame is up to 61.4 dB,simultaneously accompanied with an ultralight architecture of 0.076 g cm^(-3) and a superhigh specific shielding of 802.4 dB cm3 g^(-1).Moreover,as a proof-of-concept,the 3D-printed c-SE module is in situ integrated into core electronics,successfully replacing the traditional metal-based module to afford multiple functions for electromagnetic compatibility and thermal dissipa-tion.Thus,this scientific innovation completely makes up the blank for assembling carbon-based c-SE modules and sheds a brilliant light on developing the next generation of high-performance shielding materials with arbitrarily-customized structure for integrated electronics.

Liquid Metal Grid Patterned Thin Film Devices Toward Absorption‑Dominant and Strain‑Tunable Electromagnetic Interference Shielding

The demand of high-performance thin-film-shaped deformable electromagnetic interference(EMI)shielding devices is increasing for the next generation of wearable and miniaturized soft electronics.Although highly reflective conductive materials can effectively shield EMI,they prevent deformation of the devices owing to rigidity and generate secondary electromagnetic pollution simultaneously.Herein,soft and stretchable EMI shielding thin film devices with absorption-dominant EMI shielding behavior is presented.The devices consist of liquid metal(LM)layer and LM grid-patterned layer separated by a thin elastomeric film,fabricated by leveraging superior adhesion of aerosol-deposited LM on elastomer.The devices demonstrate high electromagnetic shielding effectiveness(SE)(SE_(T) of up to 75 dB)with low reflectance(SER of 1.5 dB at the resonant frequency)owing to EMI absorption induced by multiple internal reflection generated in the LM grid architectures.Remarkably,the excellent stretchability of the LM-based devices facilitates tunable EMI shielding abilities through grid space adjustment upon strain(resonant frequency shift from 81.3 to 71.3 GHz@33%strain)and is also capable of retaining shielding effectiveness even after multiple strain cycles.This newly explored device presents an advanced paradigm for powerful EMI shielding performance for next-generation smart electronics.

Controlled crossover of electron transport in graphene nanoconstriction:From Coulomb blockade to electron interference

The ability to control transport behaviors in nanostructure is crucial for usage as a fundamental research platform as well as a practical device.In this study,we report a gate-controlled crossover of electron transport behaviors using graphene nanoconstrictions as a platform.The observed transport properties span from Coulomb blockade-dominated single electron transmission to electron-wave interference-dominated quantum behavior.Such drastic modulation is achieved by utilizing a single back gate on a graphene nanoconstriction structure,where the size of nanostructure in the constriction and coupling strength of it to the electrodes can be tuned electrically.Our results indicate that electrostatic field by gate voltage upon the confined nanostructure defines both the size of the nanoconstriction as well as its interaction to electrodes.Increasing gate voltage raises Fermi level to cross the energy profile in the nanoconstriction,resulting in decreased energy barriers which affect the size of nanoconstriction and transmissivity of electrons.The gate-tunable nanoconstriction device can therefore become a potential platform to study quantum critical behaviors and enrich electronic and spintronic devices.

Diverse Structural Design Strategies of MXene‑Based Macrostructure for High‑Performance Electromagnetic Interference Shielding

There is an urgent demand for flexible,lightweight,mechanically robust,excellent electromagnetic interference(EMI)shielding materials.Two-dimensional(2D)transition metal carbides/nitrides(MXenes)have been potential candidates for the construction of excellent EMI shielding materials due to their great electrical electroconductibility,favorable mechanical nature such as flexibility,large aspect ratios,and simple processability in aqueous media.The applicability of MXenes for EMI shielding has been intensively explored;thus,reviewing the relevant research is beneficial for advancing the design of high-performance MXene-based EMI shields.Herein,recent progress in MXene-based macrostructure development is reviewed,including the associated EMI shielding mechanisms.In particular,various structural design strategies for MXene-based EMI shielding materials are highlighted and explored.In the end,the difficulties and views for the future growth of MXene-based EMI shields are proposed.This review aims to drive the growth of high-performance MXene-based EMI shielding macrostructures on basis of rational structural design and the future high-efficiency utilization of MXene.

Investigation and Reduction on Conducted Electromagnetic Interference Noise Mechanism for Complex Power Electronics Systems

针对复杂电子系统产生的传导EMI噪声,该文分别利用电偶极子模型、电路分析方法和散射参数方法提出了3种传导EMI噪声理论模型及其等效电路,包括因串扰引起的传导噪声模型,因接地不良引起的传导噪声模型,以及因PCB线缆阻抗失配引起的传导噪声模型。同时,还设计了一种串扰扼流圈以有效抑制因串扰引起的传导EMI噪声。实验结果表明,采用文中方法,某型商用车载导航和刷卡器能够通过GB 9254标准测试,噪声抑制效果分别可达44.8和29.28 dB V,从而验证了方法的有效性。

Thermally Conductive and UV-EMI Shielding Electronic Textiles for Unrestricted and Multifaceted Health Monitoring

Skin-attachable electronics have garnered considerable research attention in health monitoring and artificial intelligence domains,whereas susceptibility to elec-tromagnetic interference(EMI),heat accumulation issues,and ultraviolet(UV)-induced aging problems pose significant constraints on their potential applications.Here,an ultra-elas-tic,highly breathable,and thermal-comfortable epidermal sensor with exceptional UV-EMI shielding performance and remarkable thermal conductivity is developed for high-fidelity monitoring of multiple human electrophysiological signals.Via filling the elastomeric microfibers with thermally conductive boron nitride nanoparticles and bridging the insulating fiber interfaces by plating Ag nanoparticles(NPs),an interwoven thermal con-ducting fiber network(0.72 W m^(-1) K^(-1))is constructed benefiting from the seamless thermal interfaces,facilitating unimpeded heat dissipation for comfort skin wearing.More excitingly,the elastomeric fiber substrates simultaneously achieve outstanding UV protection(UPF=143.1)and EMI shielding(SET>65,X-band)capabilities owing to the high electrical conductivity and surface plasmon resonance of Ag NPs.Furthermore,an electronic textile prepared by printing liquid metal on the UV-EMI shielding and thermally conductive nonwoven textile is finally utilized as an advanced epidermal sensor,which succeeds in monitoring different electrophysiological signals under vigorous electromagnetic interference.This research paves the way for developing protective and environmentally adaptive epidermal electronics for next-generation health regulation.

Interferences in photo-detached electron spectra from a non-collinear tri-atomic anion

The electron flux oscillations in photo-detachment of a non-collinear tri-atomic anion have been studied by taking each atom of the system as a coherent source of detached-electron wave. These electron waves traversing along three different trajectories result in a quantum interference. An analytical expression of detached-electron flux is evaluated for various detached-electron energies and for different geometrical shapes of the system. The results show that the electron flux distributions exhibit molecular shape-induced oscillatory structures. These oscillations are explained using the semi- classical closed-orbit theory; the outgoing electron waves produced from one center are propagated in the vicinity of the sources at other centers. It is also observed that in a particular case our non-collinear tri-atomic system reduces to the collinear tri-atomic system recently published.

Interference-Free Determination of REEs in Electronic Waste Using ICP Optical Emission Spectroscopy

Recently, the demand for REEs （rare earth elements） has been heavily increasing, as they are used in many high-tech products （e.g., because of their specific magnetic behavior）. As a result, the supply situation for REEs is worsening and the world market is depending on Chinese exports, so that it may be worthwhile to recycle e-waste （electronic waste） in European countries. This article describes an analytical method to analyze REEs in different kinds of e-waste with the help of a simultaneous ICP-OES （ICP optical emission spectrometer）. The task is challenging because samples show significant differences in terms of major, minor and trace element concentrations. Depending on the field of application, the level of matrix elements and target elements differs completely, resulting in a wide variety of spectral interferences. The method presented in this article allows an accurate quantification of REEs as well as a high sample throughput. In addition to REEs, other elements of economic interest can be determined in the same way. The development of a sample preparation process is another important issue and considered as well.

Effects of medically generated electromagnetic interference from medical devices on cardiac implantable electronic devices: A review

As cardiac implantable electronic devices(CIED)become more prevalent,it is important to acknowledge potential electromagnetic interference(EMI)from other sources,such as internal and external electronic devices and procedures and its effect on these devices.EMI from other sources can potentially inhibit pacing and trigger shocks in permanent pacemakers(PPM)and implantable cardioverter defibrillators(ICD),respectively.This review analyzes potential EMI amongst CIED and left ventricular assist device,deep brain stimulators,spinal cord stimulators,transcutaneous electrical nerve stimulators,and throughout an array of procedures,such as endoscopy,bronchoscopy,and procedures involving electrocautery.Although there is evidence to support EMI from internal and external devices and during procedures,there is a lack of large multicenter studies,and,as a result,current management guidelines are based primarily on expert opinion and anecdotal experience.We aim to provide a general overview of PPM/ICD function,review documented EMI effect on these devices,and acknowledge current management of CIED interference.

Regularly Tuning Quantum Interference in Single-Molecule Junctions through Systematic Substitution of Side Groups with Varied Electron Effects

Investigating the quantum interference effect in single molecules is essential to comprehensively understand the underlying mechanism of single-molecule charge transport.In this study,we employed the mother molecule m-OPE and introduced a series of side groups with various electronic effects at the 2-position of the central phenyl ring,creating four daughter m-OPE derivatives.The single molecular conductivities of these molecule wires were measured using the scanning tunneling microscope breaking junction technique.Our findings demonstrate that the substitutions regularly modulate the destructive quantum interference occurring within the m-OPE molecules.By combining optical and electrochemical investigations,along with density functional theory computations,we discover that the conductivity of the molecules corresponds to the electron-donating/withdrawing ability of the substituents.Specifically,by adjusting the electron structures of the molecular backbone,we can systematically tailor the destructive quantum interference in the m-OPE molecules.

Quantum interference between Raman scattering and single-photon absorption

A new kind of quantum interference between Raman scattering and single-photon absorption is predicted theoretically, which gives an expanded view of quantum interference. Its potential application is also proposed.

Quantum Interference without Wave-Particle Duality

Interference of light and material particles is described with a unified model which does not need to assume the wave-particle duality. A moving particle is associated with a region of spatial correlated points named coherence cone. Its geometry depends on photon or particle momentum and on the parameters of the experimental setup. The final interference pattern is explained as a spatial distribution of particles caused by the coherence cone geometry. In the present context, the wave front superposition principle, wave-particle duality and wave-collapse lose their meaning. Fits of observed single electron and single molecule interference patterns together with the simulation of expected near-field molecule interference (Talbot carpet) demonstrate the model validity.

电子安全系统升压电路的传导电磁干扰建模方法

针对电子安全系统高压变换过程中产生的电磁传导干扰无法量化分析的问题,提出一种电子安全系统升压电路传导电磁干扰建模和量化分析的方法。该方法通过对电子安全系统升压电路关键器件高频等效建模构建了电子安全系统升压电路传导电磁干扰模型,开展了引信高压变换过程中传导干扰产生机理和传输路径的分析和量值仿真计算。试验和仿真结果表明,传导干扰模型能够真实反映升压过程中电路内部产生的电磁干扰特性,并可准确对传导干扰进行量化计算。

背景气体中激光Al等离子体演化的干涉诊断研究

利用自主搭建的马赫-曾德尔激光干涉诊断系统研究了空气压强在1 atm和0.1 atm以及氩气在1 atm下纳秒脉冲激光烧蚀产生Al等离子体的冲击波膨胀和电子密度演化.从测量的干涉图中提取了等离子体冲击波的膨胀轮廓,诊断了等离子体的电子密度.研究结果表明,在空气背景气压为0.1 atm时,等离子体冲击波轮廓和速度都较大;而压强在1 atm时,氩气环境中等离子体冲击波的膨胀速率和轮廓均较小.空气环境在0.1 atm下,冲击波的横向膨胀速度在50 ns时达到了约3.4 km·s^(-1),但随着延迟时间的增加快速衰减,5μs后,3种情况下的冲击波均接近声速.此外,空气环境0.1 atm下等离子体空间区域较大,整体电子密度较低;而氩气环境在1 atm下,等离子体空间区域较小,整体的电子密度较高,在300 ns时核心区域电子密度达到了10^(18) cm^(-3).结果进一步显示了背景气压对等离子体膨胀约束具有主导作用,而压强相同时,氩气环境对等离子体的约束要强于空气环境.

氖气直流放电中轴向电子密度分布的实验研究

自主搭建了激光干涉诊断系统,通过分析干涉条纹图像计算得到两路激光的相位差,再由相位差求得电子密度。通过该诊断系统研究了在柱形等离子体放电中,不同位置电子密度随电压变化的规律,以及在不同电压下轴向电子密度的分布。实验结果表明:在不同位置处,电子密度随电压的增加而增加,在增加过程中都存在电子密度平台区,在该区域内电子密度随电压缓慢增加。轴向电子密度在放电管中部存在密度峰值,当电压超过一定阈值后密度峰值由一个变成两个,在靠近阳极区域电子有一定程度的聚集。

电子通信突变非线性多频干扰检测方法仿真

电子通信技术最关键特点在于故障危险性高,若电子出现通信障碍,影响范围通常较大。为进一步优化网络通信的抗干扰性能,抵御外来信号的干扰,提出一种电子通信突变非线性多频干扰检测方法。引入调频连续波(Frequency Modulated Continuous Wave,FMCW)原理计算不同信号的之间的距离和移动速度,圈定电子通信突变信号范围,筛选出电子通信过程中的突变非线性多频干扰。采用Wigner-Ville分布对全部多频干扰信号展开谱图变换处理,获取干扰信号真实标签,同时构建突变非线性多频干扰信号对应的谱图。通过卷积神经网络提取谱图特征,将获取的特征向量输入到长短期记忆网络中检测,实现电子通信突变非线性多频干扰检测。实验测试结果表明,提出方法下干扰检测耗时在20ms内,不会受到通信内容长度阈值以及相似内容覆盖阈值波动影响,漏检率始终低于1.0%。

浅析电子通信信号的干扰与控制

本文以电子通信信号的干扰与控制作为研究主题,首先从电子通信和电子通信信号两个方面展开相应的概念解读,进而从3个方面阐述电子通信信号的主要干扰类型,并结合实际指出产生干扰的原因,最后有针对性地从尽可能的消除硬件干扰、注意规避电子设备产生的干扰以及有层次的排查和解决同频干扰3个方面提出电子通信信号受到干扰的控制措施,希望能进一步保障我国电子通信信号质量。

电子通信突变非线性多频干扰检测方法

电子通信中同频段窄带信号通常含有多种不同频谱的非线性信号,对通信造成突发性干扰。此类非线性信号干扰的多频段表现性强且特征种类多,检测难度较大。为此提出一种考虑动态特征的突变非线性多频干扰检测方法。构建电子通信模型,采集信号样本,根据时域逐步增加的关系完成信号的扩频。计算扩频前和扩频后的幅度差值,根据信号跟随时间变化的递推关系推导出每个源点区域的实时状态特征。采用DFT多级模型按照特征大小顺序逐一检测,若信号超过门限值,则输入到下一级检测层中;若信号低于门限值,直接输出非线性多频干扰检测结果。实验证明:研究方法能够高精度检测电子通信突变非线性多频干扰的时域和频域幅值,说明上述方法的应用性能更好,研究价值较高。

一种顾及舱内OBE干扰的改进航磁补偿方法

航磁干扰补偿是飞行器地磁导航的必要环节,目前在航空磁探等领域广泛应用的Tolles-Lawson(T-L)模型需要辅以延伸杆或拖拽等方式,难以满足地磁导航对于不改变飞行器气动外观的应用需求。因此,提出了一种能够适应磁力计舱内安装的航磁补偿方法。该方法在T-L模型的基础上,扩展了机载电子设备(OBE)干扰项。同时,针对舱内磁干扰频域分布未知和干扰来源复杂的问题,设计了基于频谱拐点计算的滤波器截止频率确定方法和基于电流及电压相关性贡献度的模型输入特征选择方法。最后,采用主成分分析(PCA)降低模型复共线性的影响。通过一组开源的有人机实飞磁测数据对方法进行了验证,实验结果表明该方法对舱内磁测数据的补偿精度优于其他方法,最佳补偿结果与真值之间的均方根误差为1.71 nT,基本满足地磁导航终端的精度要求。