Mn^(4+) activated phosphors in photoelectric and energy conversion devices

Owing to their high luminous efficiency and tunable emission in both red light and far-red light regions,Mn^(4+)ion-activated phosphors have appealed significant interest in photoelectric and energy conversion devices such as white light emitting diode(W-LED),plant cultivation LED,and temperature thermometer.Up to now,Mn^(4+)has been widely introduced into the lattices of various inorganic hosts for brightly redemitting phosphors.However,how to correlate the structure-activity relationship between host framework,luminescence property,and photoelectric device is urgently demanded.In this review,we thoroughly summarize the recent advances of Mn^(4+)doped phosphors.Meanwhile,several strategies like co-doping and defect passivation for improving Mn^(4+)emission are also discussed.Most importantly,the relationship between the protocols for tailoring the structures of Mn^(4+)doped phosphors,increased luminescence performance,and the targeted devices with efficient photoelectric and energy conversion efficiency is deeply correlated.Finally,the challenges and perspectives of Mn^(4+)doped phosphors for practical applications are anticipated.We cordially anticipate that this review can deliver a deep comprehension of not only Mn^(4+)luminescence mechanism but also the crystal structure tailoring strategy of phosphors,so as to spur innovative thoughts in designing advanced phosphors and deepening the applications.

High-capacity Bi_(2)O_(3) anode for 2.4 V neutral aqueous sodium-ion battery-supercapacitor hybrid device through phase conversion mechanism

Aqueous battery-supercapacitor hybrid devices(BSHs)are of great importance to enrich electrochemical energy storage systems with both high energy and power densities.However,further improvement of BSHs in aqueous electrolytes is greatly hampered by operating voltage and capacity limits.Different from the conventional intercalation/de-intercalation mechanism,Bi_(2)O_(3) implements charge storage by a reversible phase conversion mechanism.Herein,taking Bi_(2)O_(3) electrode with wide potential window(from-1.2 to 1 V vs.saturated calomel electrode)and high capacity as battery-type anode,we propose that the overall performance of aqueous BSHs can be greatly upgraded under neutral condition.By paring with stable layer-structuredδ-MnO_(2) cathode,a sodium-ion Bi_(2)O_(3)//MnO_(2) BSH with an ultrahigh voltage of 2.4 V in neutral sodium sulfate electrolyte is developed for the first time.This hybrid device exhibits high capacity(~215 C g^(-1) at 1 mA cm^(-2)),relatively long lifespan(~77.2%capacity retention after 1500 cycles),remarkable energy density(71.7 Wh kg^(-1)@400.5 W kg^(-1))and power density(3204.3 W kg^(-1)@18.8 Wh kg^(-1)).Electrochemical measurements combining a set of spectroscopic techniques reveal the reversible phase conversion between bismuth oxide and metallic bismuth(Bi_(2)O_(3)?Bi0)through Bi^(2+) transition phase in neutral sodium sulfate solution,which can deliver multielectron transfer up to 6,leading to the high-energy BSHs.Our work sheds light on the feasibility of using Bi_(2)O_(3) electrode under neutral condition to address the issue of narrow voltage and low capacity for aqueous BSHs.

Light energy conversion device for photocatalyst 2.0%WO_3-TiO_2 with oxygen vacancies for water splitting

Using carbon felt,polytetrafluoroethylene latex and powder catalyst to assembly a light energy conversion device,the photocatalytic activity of catalyst 2.0%WO3-TiO2(2%WO3 compounding TiO2) with oxygen vacancies was studied through the water splitting for O2 evolution,using a high pressure mercury lamp as the light source and Fe 3+ as the electron acceptor in two different devices:an ordinary photolysis device with catalyst powder suspending through a magnetic stirrer and a self-assembly light energy conversion device.The results show that after 12 h irradiation,the photocatalytic activity of 2.0%WO3-TiO2 with oxygen vacancies in the self-assembly light energy conversion device is higher than that of the ordinary photolysis device,and the amount of oxygen evolution is about 12 and 9 mmol/L respectively in these two devices.After 12 h,the rates of O2 evolution are slow in each device and the photocatalyst almost loses the photoactivity in the ordinary photolysis device.So,compared with the ordinary photocatalytic device,the rate of oxygen evolution and the life time of the catalyst are improved in the self-assembly light energy conversion device.

Oxidative Molecular Layer Deposition Tailoring Eco-Mimetic Nanoarchitecture to Manipulate Electromagnetic Attenuation and Self-Powered Energy Conversion

Advanced electromagnetic devices,as the pillars of the intelligent age,are setting off a grand transformation,redefining the structure of society to present pluralism and diversity.However,the bombardment of electromagnetic radiation on society is also increasingly serious along with the growing popularity of"Big Data".Herein,drawing wisdom and inspiration from nature,an eco-mimetic nanoarchitecture is constructed for the first time,highly integrating the advantages of multiple components and structures to exhibit excellent electromagnetic response.Its electromagnetic properties and internal energy conversion can be flexibly regulated by tailoring microstructure with oxidative molecular layer deposition(oMLD),providing a new cognition to frequency-selective microwave absorption.The optimal reflection loss reaches≈−58 dB,and the absorption frequency can be shifted from high frequency to low frequency by increasing the number of oMLD cycles.Meanwhile,a novel electromagnetic absorption surface is designed to enable ultra-wideband absorption,covering almost the entire K and Ka bands.More importantly,an ingenious self-powered device is constructed using the eco-mimetic nanoarchitecture,which can convert electromagnetic radiation into electric energy for recycling.This work offers a new insight into electromagnetic protection and waste energy recycling,presenting a broad application prospect in radar stealth,information communication,aerospace engineering,etc.

In-fiber photoelectric device based on graphene-coated tilted fiber grating

Graphene and related two-dimensional materials have attracted great research interests due to prominently optical and electrical properties and flexibility in integration with versatile photonic structures.Here,we report an in-fiber photoelec-tric device by wrapping a few-layer graphene and bonding a pair of electrodes onto a tilted fiber Bragg grating(TFBG)for photoelectric and electric-induced thermo-optic conversions.The transmitted spectrum from this device consists of a dense comb of narrowband resonances that provides an observable window to sense the photocurrent and the electrical injection in the graphene layer.The device has a wavelength-sensitive photoresponse with responsivity up to 11.4 A/W,allowing the spectrum analysis by real-time monitoring of photocurrent evolution.Based on the thermal-optic effect of electrical injection,the graphene layer is energized to produce a global red-shift of the transmission spectrum of the TF-BG,with a high sensitivity approaching 2.167×10^(4)nm/A^(2).The in-fiber photoelectric device,therefore as a powerful tool,could be widely available as off-the-shelf product for photodetection,spectrometer and current sensor.

Elastic twisting metamaterial for perfect longitudinal-torsional wave mode conversion

In this work,we design a twisting metamaterial for longitudinal-torsional(L-T)mode conversion in pipes through exploring the theory of perfect transmodal FabryPerot interference(TFPI).Assuming that the axial and radial motions in pipes can be decoupled,we find that the metamaterial can be designed in a rectangular coordinate system,which is much more convenient than that in a cylindrical system.Numerical calculation with detailed microstructures shows that an efficient L-T mode conversion can be obtained in pipes with different radii.In addition,we fabricate mode-converting microstructures on an aluminum pipe and conduct ultrasonic experiments,and the results are in good agreement with the numerical calculations.We expect that the proposed LT mode-converting metamaterial and its design methodology can be applied in various ultrasonic devices.

串行设备与DeviceNet总线协议转换的实现

目前,工业现场许多一次和二次仪表都带有RS-232/RS-485串行接口,可通过协议转换装置将这些串行设备应用到DeviceNet总线系统中。文中对串行设备和DeviceNet总线协议转换的关键问题进行了分析,提出了基本的解决思路和实现方法。

Investigation on the Oscillating Buoy Wave Power Device

An oscillating buoy wave power device (OD) is a device extracting wave power by an oscillating buoy. Being excited by waves, the buoy heaves up and down to convert wave energy into electricity by means of a mechanical or hydraulic device. Compared with an Oscillating Water Column (OWC) wave power device, the OD has the same capture width ratio as the OWC does, but much higher secondary conversion efficiency. Moreover, the chamber of the OWC, which is the most expensive and difficult part to be built, is not necessary for the OD, so it is easier to construct an OD. In this paper, a numerical calculation is conducted for an optimal design of the OD firstly, then a model of the device is built and, a model test is carried out in a wave tank. The results show that the total efficiency of the OD is much higher than that of the OWC and that the OD is a promising wave power device.

Advanced Power Module Packaging and Integration Structures for High Frequency Power Conversion：From Silicon to GaN

The emerging of commercial high-voltage gallium nitride(GaN) power devices provides extraordinary switching performance over silicone devices, which enables high-voltage power conversion switching at megahertz range.Such outstanding features also pose strong challenges for device packaging design since the package parasitics can significantly influence the device switching characteristics, and thus can shadow the advantages brought by GaN devices. Designers have been dealing with these challenges brought by high du/dt and high-frequency switching operation even since the silicon(Si) era when fast switching Si MOSFET is first developed and came up with lots of inspiring advanced power module packaging structures to mitigate the problems.This paper presents a review of advanced power module packaging and integration structures that are suitable for high frequency power conversion.The review covers the heritage from the high frequency Si MOSFET packaging to the state-of-the-art for GaN devices.

Flux-to-voltage characteristic simulation of superconducting nanowire interference device

Inspired by recent discoveries of the quasi-Josephson effect in shunted nanowire devices,we propose a superconducting nanowire interference device in this study,which is a combination of parallel ultrathin superconducting nanowires and a shunt resistor.A simple model based on the switching effect of nanowires and fluxoid quantization effect is developed to describe the behavior of the device.The current-voltage characteristic and flux-to-voltage conversion curves are simulated and discussed to verify the feasibility.Appropriate parameters of the shunt resistor and inductor are deduced for fabricating the devices.

On the Absence of Carrier Drift in Two-Terminal Devices and the Origin of Their Lowest Resistance Per Carrier R_k=h/Q²

After a criticism on today’s model for electrical noise in resistors, we pass to use a Quantum-compliant model based on the discreteness of electrical charge in a complex Admittance. From this new model we show that carrier drift viewed as charged particle motion in response to an electric field is unlike to occur in bulk regions of Solid-State devices where carriers react as dipoles against this field. The absence of the shot noise that charges drifting in resistors should produce and the evolution of the Phase Noise with the active power existing in the resonators of L-C oscillators, are two effects added in proof for this conduction model without carrier drift where the resistance of any two-terminal device becomes discrete and has a minimum value per carrier that is the Quantum Hall resistance Rk=h/q2

Cascadability of Uniform Fibre Bragg Grating for 40 Gbit/s RZ-OOK to NRZ-OOK Conversion

The cascadability of uniform fibre Bragg grating for 40 Gbit/s return to zero on-off keying to non-return to zero on-off keying format conversion has been shown using OptSim simulation program. The main idea of this approach is use of specially designed uniform fibre Bragg grating with appropriate transfer function for shaping of 40 Gbit/s return to zero on-off keying optical spectrum. Error free performance is achieved after four cascades of uniform fibre Bragg grating with different reflectivity values.

波浪能供电观测浮标防腐方案设计及仿真

针对波浪能供电观测浮标的结构组成,分析其工作原理、运动特性、各系统处的海洋腐蚀环境,将浮标划分成多个海洋污损区域。基于目前的防腐方法和浮标复杂的海洋腐蚀环境,综合考虑成本及施工时效性,提出一种防腐油漆涂层加阴极保护双组合的防腐方法,并进行外加电流阴极保护防腐系统及关键参数的设计。通过数值模拟,确定该系统布置在浮标主浮体侧面可实现较好的防腐效果。最后,提出两种防腐系统位置布置方案。

伺服阀产线的智能协议转换技术研究

针对多源异构设备数据之间互联互通的实际需求,提出了一种多源数据智能协议转换技术。以数据协议为核心,将采集的信息来源对象化后导入协议解析数据库,归一化后,基于不同应用需求的重构协议,如OPC UA(OPC Unified Architecture),输出XML(Extensible Markup Language)文件或存储至服务器,最后将数据库接入到产线的数据集成管控系统进行数据分析和可视化展示。以民机伺服阀产线产品调试设备为研究对象,采集油源、测试台和试验箱等设备状态和运行参数,对提出的数据协议转换技术进行了验证。实验证明,所提出的方法实现了油源、测试台和试验箱等设备数据之间的互联互通,为多源异构设备数据采集的融合应用提供了基础。

基于方形开口环的太赫兹偏振转换器设计

基于方形开口环与金属棒组合的超材料结构,提出一种新型透射式太赫兹偏振转换器件。研究了基本结构单元的不同组合方式对偏振转换特性的影响,并通过优化结构单元的相关参数,提高了偏振转换功能的工作带宽。最终在0.45~1.30 THz范围内实现了高效的X-Y方向交叉极化偏振转换,有望用于集成化太赫兹偏振转换器件的研究和应用中。

可穿戴纤维基能源转换器件研究进展

随着智能可穿戴设备的普及,其能源供应问题愈加突出,一种绿色且高效的供能系统有待被研发。纤维基能源转换器件凭借着其优异的可集成性和宏观可调性,在柔性穿戴领域受到了越来越多的关注,有望成为解决新一代能源供给问题的有效方案。为进一步深化对纤维基能源转换方案的认识,本文主要回顾了压电、热电和磁电纤维基能源转换器件的最新研究与应用进展,重点讨论了压电纤维、热电纤维和磁电纤维的制备方法、性能分析和可穿戴应用,最后提出了纤维基能源转换器件在应用中所面临的问题与挑战,并对其未来的发展趋势进行了展望。

振荡浮子式波能装置的功率计算分析及参数设计

波浪能是重要的可再生资源之一,提高波浪能装置的能量捕获率是波浪能规模化利用的关键。本文对波浪能的能量转换装置进行了研究,针对装置于不同摇荡条件下的最大平均输出功率、最优阻尼系数及相关参数进行演化分析及求解。利用牛顿定律及质心系、转动惯量等建立二自由度、四自由度波浪能转换装置耦合运动模型,基于时间离散化的差分原理求解,同时采用模拟退火算法降低时间复杂度,提出了改良的粒子群算法,得到较为准确的结果,为实际工程中波浪能的高效采集提供思路和途径。

继电保护测试仪自动检测系统设计

继电保护测试仪是对继电保护装置调试和检验的重要仪器。为了进一步提高继电保护测试仪的检测精度、稳定性和检测效率,设计了基于LabVIEW的继电保护测试仪自动检测系统。该系统采用LabVIEW模块化的编程思想,实现继电保护测试仪的自动检测、手动检测、保存报告等功能。为了解决继电保护测试仪的输出为三相,而万用表和示波器仅支持单相测试的问题,设计了输出转换装置。基于转换装置,可以在测试开始前一次性完成所有接线,并在测试过程中根据不同校准项目进行测试回路自动切换。功能测试结果表明,该系统能满足检验标准化、报告标准化和闭环自动测试要求。该系统对其他二次测量设备的自动检测校准有一定的借鉴意义。

先进控制技术在煤制甲醇变换装置上的应用

介绍了某甲醇厂采用先进控制系统对生产过程监测控制的情况,变换炉超温或者低温的现象大幅降低90%以上,出口CO指标稳定性比人工控制波动幅度减少40%以上,合成岗位的产量提升了0.5%。