X波段多功能频率合成器设计

文章介绍了一种X波段多功能频率合成器的设计方法,该方法以直接数字频率合成(DDFS)和直接式模拟合成技术为基础,通过优化频率规划和引入相位噪声清除技术,改善了频率合成器杂散和相位噪声性能。雷达激励器采用了"任意波形产生(AWG)+IQ调制"结构,除产生雷达激励波形外,兼具回波模拟器功能,实现了一个硬件平台,两种功能的一体化设计,具有良好的工程应用价值。文章给出了原理框图,并对相位噪声、杂散等方面做重点的介绍和分析,文末给出了测试结果。     

CdSe纳米晶的制备及性能表征

以巯基乙酸（RSH）为稳定剂，在水溶液中合成了稳定的CdSe纳米颗粒，通过选择沉淀得到尺寸为1.8-4.0nm的样品。通过紫外－可见吸收光谱、X－射线粉末衍射（XRD）、透射电镜（TEM）和高分辨透射电镜（HRTEM）对样品的结构及量子限制效应影响下的光学特性进行了表征；将长链的表面活性剂接枝在纳米颗粒表面，从而使只能在水溶液中分散的纳米颗粒在有机溶剂中也能很好地分散，并得到了单个颗粒的高分辨电镜图像。     

High‐Yield Synthesis of Multifunctional Tellurium Nanorods to Achieve Simultaneous Chemo‐Photothermal Combination Cancer Therapy

Tellurium (Te) is an important semiconductor material with low band‐gap energy, which has attracted considerable attention in recent years, due to its special chemical and physical properties and wide potential in electrochemistry, optoelectronics, and biological fields. This study demonstrates a facile and high‐yield synthesis strategy of Te nanorods (PTW‐TeNRs) decorated by polysaccharide–protein complex, which can achieve simultaneous chemo‐photothermal combination therapy against cancers. PTW‐TeNRs alone possess high stability under physiological conditions, potent anticancer activities through induction of reactive oxygen species overproduction, and high selectivity among tumor and normal cells. More importantly, they exhibit strong near‐infrared (NIR) absorbance and good photothermal conversion ability from NIR light to heat energy. Furthermore, in combination with NIR laser irradiation, PTW‐TeNRs exhibit excellent chemo‐photothermal efficiency and low toxicity as evidenced by highly efficient tumor ablation ability, but show no obvious histological damage to the major organs. Taken together, this study provides a valid tactic for facile synthesis of multifunctional tellurium nanorods for efficient and combinational cancer therapy.     

Multifunctional Synthesis Approach of In:CuCrO2 Nanoparticles for Hole Transport Layer in High‐Performance Perovskite Solar Cells

While there are very limited studies of doped ternary metal oxide based hole transport materials, a multifunctional synthesis approach of In doped CuCrO₂ nanoparticles (NPs) as efficient hole transport layers (HTLs) including simplifying the synthesis requirements is proposed, enabling doping and achievement of treatment‐free HTLs. Remarkably, compared with conventional methods for synthesizing CuCrO₂ NPs, the newly proposed azeotropic promoted approach dramatically reduces the reaction time by 90% and the calcination temperature by one‐third, which not only promotes high throughput production but also reduces power consumption and cost in synthesis. Equally important, indium is successfully doped into CuCrO₂, which is fundamentally difficult in low temperature processes. The In doping offers less d–d transition of Cr³⁺ and p‐type doping characteristics for improving HTL transmittance and conductivity, respectively. Interestingly, In doped CuCrO₂ HTL with these improvements can be achieved by a simple ambient‐condition process and exhibits thermal stability up to 200 °C, which allows perovskite solar cells (PSCs) to achieve a power conversion efficiency of 20.54%. Meanwhile, the devices show good repeatability and photostability. Consequently, the work contributes to establishing a simple approach to realize pristine and doped multinary oxides based HTL for the development of practical and high performing PSCs.     

多功能电路模块设计

多功能电路模块是由印制电路板、电子元器件、信号源、仪器仪表等构建成的多网孔的电路,电路设计中各支路预留插孔,可根据课堂教学进程的需要调整信号源类型,构建成不同的电路类型,如单电源供电或者多电源供电的直流电路、交流电路;各支路可串接电流表,电阻两端可并联接入电压表,用以检测各支路元件的电路参数。多功能教学电路具有信号源的可外接性、电路结构的可调整性,可以灵活地运用到高职高专院校机械类、电子类、汽车类的《电路基础》课程的教学过程中,从而在不同的教学阶段可以构建不同的项目进行教学,围绕特定的项目,可以开展融"教、学、做"于一体的"理实一体化"教学模式。     

An Alternative Approach to Constructing Solution Processable Multifunctional Materials: Their Structure,Properties, and Application in High‐Performance Organic Light‐Emitting Diodes

A new series of full hydrocarbons, namely 4,4′‐(9,9′‐(1,3‐phenylene)bis(9H‐fluorene‐9,9‐diyl))bis(N,N‐diphenylaniline) (DTPAFB), N,N′‐(4,4′‐(9,9′‐(1,3‐phenylene)bis(9H‐fluorene‐9,9‐diyl))bis(4,1‐phenylene))bis(N‐phenylnaphthalen‐1‐amine) (DNPAFB), 1,3‐bis(9‐(4‐(9H‐carbazol‐9‐yl)phenyl)‐9H‐fluoren‐9‐yl)benzene, and 1,3‐bis(9‐(4‐(3,6‐di‐tert‐butyl‐9H‐carbazol‐9‐yl)phenyl)‐9H‐fluoren‐9‐yl)benzene, featuring a highly twisted tetrahedral conformation, are designed and synthesized. Organic light‐emitting diodes (OLEDs) comprising DNPAFB and DTPAFB as hole transporting layers and tris(quinolin‐8‐yloxy)aluminum as an emitter are made either by vacuum deposition or by solution processing, and show much higher maximum efficiencies than the commonly used N,N′‐di(naphthalen‐1‐yl)‐N,N′‐diphenylbiphenyl‐4,4′‐diamine device (3.6 cd A^?1) of 7.0 cd A^?1 and 6.9 cd A^?1, respectively. In addition, the solution processed blue phosphorescent OLEDs employing the synthesized materials as hosts and iridium (III) bis[(4,6‐di‐fluorophenyl)‐pyridinato‐N, C²] picolinate (FIrpic) phosphor as an emitter present exciting results. For example, the DTPAFB device exhibits a brightness of 47 902 cd m^?2, a maximum luminescent efficiency of 24.3 cd A^?1, and a power efficiency of 13.0 lm W^?1. These results show that the devices are among the best solution processable blue phosphorescent OLEDs based on small molecules. Moreover, a new approach to constructing solution processable small molecules is proposed based on rigid and bulky fluorene and carbazole moieties combined in a highly twisted configuration, resulting in excellent solubility as well as chemical miscibility, without the need to introduce any solubilizing group such as an alkyl or alkoxy chain.     

用矢量码书和动态内插限制方法解决语音生成逆向解的非唯一性问题

 本文研究运用矢量码书和动态内插限制的方法解决语音生成逆向解的非唯一性问题.表征声道的对数截面积函数的限带傅立叶余弦展开包括了偶次项,采用可变声道长度;频域声学目标增加了前N个零点频率;结合腔包形声学——几何形态映射矢量码书,为声学目标匹配得到过渡音的起始和结尾端点的零点与声道长度,并用内插方法来限定过渡点的零点频率和声道长度,从而解决非唯一性问题.计算机仿真实验表明了本方法的有效性.     

Multifunctional Barium Titanate Coated Carbon Fibers

Multifunctional materials have received significant research interest due to the potential for performance enhancements over traditional materials through the integration of responsive properties. Composite materials are ideally suited for use as multifunctional materials due to their use of two or more phases and the ease at which their properties can be anisotropically tailored. Here, a methodology for the integration of ferroelectricity into a fiber reinforced polymer composite is presented by synthesizing a barium titanate nanowire film on the surface of carbon fibers using a novel two‐step hydrothermal process. A refined piezoelectric force microscopy method is used to quantify the piezoelectric properties of the core–shell fiber resulting in an average d₃₃ of 31.6 ± 14.5 pm V^?1 and an average d₃₁ of ?5.4 ± 3.2 pm V^?1. The multifunctionality of this piezoelectric coated fiber is demonstrated through excitation of a cantilevered fiber with a 0.5 g sinusoidal base acceleration at the fiber's fundamental resonant frequency, producing a root‐mean‐square voltage of 16.4 mV. This result demonstrates the ferroelectric properties of the multifunctional structural fiber and its application for sensing and energy harvesting.     

多功能电波暗室应用技术

该文介绍了电磁兼容测试需要的多功能电波暗室,成为多功能电波暗室应具备的基本功能,对满足标准要求的多功能电波暗室所需具备的性能指标进行描述及相应的测试要求,如基本的NSA,Svswr,FU。对在多功能电波暗室中进行不同项目测试时所对应的场地布置进行了分析,最后对多功能电波暗室的优劣进行了总结。     

多功能浇水器的设计

为满足对花卉爱好者家庭中的盆花或农林产业中的植物进行自动地浇水的需求.采用自制传感器,结合AT89C52单片机芯片和其它相关器件研究设计自动多功能浇水器.通过测试表明,多功能浇水器具有设置灵活,数字显示,自动分析土壤水分,成本较低的特点.此设备可以广泛应用在上述场合,达到预期的设计目的和要求.     

基于CCⅡ的电流模式多功能滤波器

提出两个三输入、单输出多功能电流模式滤波器,每个滤波器都由三个第二代电流传输器(CC Ⅱ)及一些接地电阻和电容组成.通过选择滤波器的输入端,即可在输出端得到低通、高通、带通、陷波和全通五种基本滤波功能.与同类文献[1,2]相比,不但电路简单,而且角频率ωn和品质因素Q可实现独立可调,无源灵敏度较低.同时,对其中的一种滤波器进行了硬件实现,并对滤波器的低通、高通和带通性能进行了测量和分析,充分证明了该滤波器的优良性能.     

Water‐Powered Cell‐Mimicking Janus Micromotor

Cell derivatives have received increasing attention due to their unique ability to mimic many of the natural properties displayed by their source cells. Integration of cell‐derived natural materials with synthetic subjects can be applied toward the development of novel biomedical nano/microscale devices for a wide range of applications, including drug delivery and biodetoxification. Herein, a cell membrane functionalized magnesium‐based Janus micromotor, powered by water, that mimics natural motile cells is reported. The new cell‐mimicking Janus micromotor is constructed by integrating red blood cell (RBC) membranes, gold nanoparticles (AuNPs), and alginate (ALG) onto the exposed surface areas of magnesium microparticles that are partially embedded in Parafilm. The resulting RBC membrane‐coated magnesium (RBC‐Mg) Janus micromotors display an efficient and guided propulsion in water without any external fuel, as well as in biological (albumin‐rich) media with no apparent biofouling, mimicking the movement of natural motile cells. The effective RBC membrane coating bestows the RBC‐Mg Janus micromotors with unique capability for absorbing and neutralizing both biological protein toxins and nerve agent simulants. Such detoxification ability is facilitated greatly by the water‐driven motion of the motors. The RBC‐Mg Janus micromotors represent an exciting progress toward cell‐mimicking microscale motors that hold great promise for diverse biomedical and biodefense applications.     

Multifunctional ZnO-Based Thin-Film Bulk Acoustic Resonator for Biosensors

Zinc oxide (ZnO) and its ternary alloy magnesium zinc oxide (Mg _x Zn_1−x O) are piezoelectric materials that can be used for high-quality-factor bulk acoustic wave (BAW) resonators operating at GHz frequencies. Thin-film bulk acoustic resonators (TFBARs) are attractive for applications in advanced communication and in various sensors as they offer the capability of monolithic integration of BAW resonators with radio-frequency integrated circuits (RF ICs). In this paper we report Mg _x Zn_1−x O-based TFBAR biosensors. The devices are built on Si substrates with an acoustic mirror consisting of alternating quarter-wavelength silicon dioxide (SiO₂) and tungsten (W) layers to isolate the TFBAR from the Si substrate. High-quality ZnO and Mg _x Zn_1−x O thin films are achieved through a radio-frequency (RF) sputtering technique. Tuning of the device operating frequency is realized by varying the Mg composition in the piezoelectric Mg _x Zn_1−x O layer. Simulation results based on a transmission-line model of the TFBAR show close agreement with the experimental results. ZnO nanostructures are grown on the TFBAR’s top surface using metal- organic chemical vapor deposition (MOCVD) to form the nano-TFBAR sensor, which offers giant sensing area, faster response, and higher sensitivity over the planar sensor configuration. Mass sensitivity higher than 10³ Hz cm²/ng is achieved. In order to study the feasibility of the nano-TFBAR for biosensing, the nanostructured ZnO surfaces were functionalized to selectively immobilize␣DNA, as verified by hybridization with its fluorescence-tagged DNA complement.     

基于单片机的多功能智能机器人设计

主要介绍了一种具有娱乐功能和安防功能的智能机器人的设计方案,该方案以英飞凌16位单片机XE162FN为核心,并且通过蓝牙以及全球移动通信系统(GSM,Global System for MobileCommunications)方式实现无线通讯,包含娱乐和安防两大主要功能。娱乐方面可以实现机器人多方式遥控、智能跟随、移动中避障、彩灯随拍手频率闪烁、音乐播放等功能;安防方面可以实现检测家中煤气泄露或者火灾发生时的烟雾,并发出本地声光报警以及通过GSM网络发送报警短信给指定手机号码的功能。     

便携式多功能交流电源的设计

供电系统中,由于现场停电,往往电能表应用起来极不方便,便携式多功能电源可以有效解决上述问题。便携式多功能电源应用了高频链的逆变电源拓扑结构,减小了电源的体积和重量;同时采用了SPWM技术,并通过电压单闭环的PI调节优化了输出;可以分别输出三个等级的交流电。介绍了电源的硬件电路、软件程序,并且通过实验证明便携式多功能电源输出波形好、工作可靠。     

Electromechanical and photoelectric properties of a novel semiconducting Janus InGaSSe monolayer

In recent years, Janus two-dimensional (2D) materials have received extensive research interests because of their outstanding electronic, mechanical, electromechanical, and optoelectronic properties. In this work, we explore the structural, electromechanical, and optoelectronic properties of a novel hypothesized Janus InGaSSe monolayer by means of first-principles calculations. It is confirmed that the Janus InGaSSe monolayer indeed show extraordinary charge transport properties with intrinsic electron mobility of 48 139 cm²/(V·s) and hole mobility of 16 311 cm²/(V·s). Both uniaxial and biaxial strains can effectively tune its electronic property. Moreover, the Janus InGaSSe monolayer possesses excellent piezoelectric property along both in-plane and out-of-plane directions. The results of this work imply that the Janus InGaSSe monolayer is in fact an efficient photocatalyst candidate, and may provide useful guidelines for the discovery of other new 2D photocatalytic and piezoelectric materials.

     

Room Temperature Multifunctional Organophosphorus Gels and Liquid Crystals

A new series of extended dithieno[3,2‐b:2',3'‐d]phospholes with dendritic and non‐dendritic architectures involving phenylenevinylene as well as Fréchet‐type dendrons is presented. Modification of the phosphorus center with Pd allows for the generation of a dimeric dendrimer with Pd‐center. The synthetic strategy employed balances the rigid main scaffold with the flexibility of the dendrons in order to keep control of supramolecular self‐organization features. All the structures show a high photoluminescence in both solution and solid state, which is further intensified via energy transfer from the dendrons to the core. In terms of self‐organization in solution, three of the derivatives which bear an extended phosphole unit as common moiety are able to gel a variety of organic solvents at room temperature independently from the nature of their substituents. Notwithstanding, the dimeric dendrimer with Fréchet‐type dendrons is only able to display gel properties at low temperature. All gels exhibit pronounced photoluminescence properties that can be tuned by variation of the solvent and the temperature. In absence of solvent, the phosphole derivatives exhibit, moreover, liquid‐crystalline mesomorphism features. While three of the compounds present stable and highly luminescent columnar hexagonal phases at room temperature, the fourth species was found to be crystalline in the thermal range up to its isotropic state. Finally as proof of concept, the multifunctionality of these materials is demonstrated in an electrochromic device.     

Multifunctional Hybrid Polymer‐Based Porous Materials

Polymer‐based porous hybrid materials (PHMs) carrying inorganic nanoparticles on the surface of pores have important applications in chemical and biological sensing, in chromatography, and in heterogeneous catalysis. This Feature Article provides an overview of the recent developments in the synthesis and fabrication of multifunctional PHMs using polymerization‐induced phase separation. Exemplary applications of a PHM coated with gold nanorods were demonstrated for the simultaneous detection of different analytes using surface enhanced Raman scattering (SERS) spectroscopy and fluorescence microscopy.     

Calcium Phosphate Microcapsules as Multifunctional Drug Delivery Devices

More challenging active pharmaceutical ingredients are entering the market, spurring the introduction of novel drug delivery strategies that necessitate a paradigm shift from exhausted excipients to materials with combined actions and multiple functionalities. In this study, an inorganic calcium phosphate microparticle with a hollow internal structure is introduced as a biocompatible and multifunctional microcapsule: the template inverted particle (TIP). A robust process is presented to create a unique particle geometry, which is characterized by a particle size of 20 µm and a hollow cavity enclosed by a specially engineered porous shell. This study focuses on the characterization of TIP as an excipient for the design of solid dosage forms. The cavities in the particle centers serve as an encapsulation space, resulting in boosted water uptake capacity of 5.3 cm³ g⁻¹. Benefiting from the material's high wettability and water uptake rates, TIP tablets immediately disperse in the oral cavity. Mechanistic studies reveal a viscoelastic behavior of empty TIP microcapsules in accordance with the Kelvin–Voigt model of a parallel spring-dashpot configuration. The unique particle geometry is maintained during compaction thanks to its exceptional structural integrity. This study demonstrates how multifunctional TIP microcapsules can be applied as a pharmaceutical drug delivery device.     

基于单片机的多功能电路测试平台

介绍了一种基于AT89C51单片机的多功能电路测试平台，给出了测试平台的硬件组成和软件实现方法。该测试平台主要完成对某专用计算器中央控制电路板的电路、器件的在线测试。