基于AuPd/CNT敏感材料的电化学传感器对对乙酰氨基酚的检测

金属纳米材料由于其自身优异的催化性能成为电化学催化剂发展最为迅速的一类催化材料,贵金属催化剂的性能尤为明显。本文利用湿化学法合成了粒径为(8.26±0.2)nm AuPd双金属纳米材料,并与多壁碳纳米管进行复合获得AuPd/CNT复合材料,以此作为敏感材料构建了电化学传感器。Au为主催化剂,Pd为助催化剂,双金属催化剂的协同作用有效地提升了催化性能。以AuPd双金属纳米材料构建的电化学传感器对对乙酰氨基酚(PA)的定量测定具有宽的线性范围(4~1000μmol/L)、低的检测限(0.05μmol/L)。将传感器用于感冒片剂中对乙酰氨基酚的定量测定取得满意的结果,表明AuPd双金属纳米材料在构建电化学传感器用于PA检测中具有良好的应用前景。     

Complex Hollow Bowl-Like Nanostructures: Synthesis,Application, and Perspective

Contourable design and synthesis in nanomaterial morphology are among the most attractive fields in material science. Among the various nanomaterials, hollow bowl-like nanomaterials have shown promising potential and achieved great success in many different domains, such as lithium-ion batteries, supercapacitors, and electro- and photochemical catalysts. The unique physicochemical properties of hollow bowl-like nanomaterials have attracted enormous interest from scientists worldwide. Here, recent researches into bowl-like nanomaterials, including: (i) synthesis methods, such as the no-template, no-patchy template, and patchy template methods; (ii) applications in lithium/sodium/potassium ion-based batteries, microwave absorption, water-splitting reactions, and so on are reviewed; and (iii) the problems and challenges are also discussed.     

Metal–Organic Framework Nanosheets: Programmable 2D Materials for Catalysis,Sensing, Electronics,and Separation Applications

Metal–organic framework nanosheets (MONs) have recently emerged as a distinct class of 2D materials with programmable structures that make them useful in diverse applications. In this review, the breadth of applications that have so far been investigated are surveyed, thanks to the distinct combination of properties afforded by MONs. How: 1) The high surface areas and readily accessible active sites of MONs mean they have been exploited for a variety of heterogeneous, photo-, and electro-catalytic applications; 2) their diverse surface chemistry and wide range of optical and electronic responses have been harnessed for the sensing of small molecules, biological molecules, and ions; 3) MONs tunable optoelectronic properties and nanoscopic dimensions have enabled them to be harnessed in light harvesting and emission, energy storage, and other electronic devices; 4) the anisotropic structure and porous nature of MONs mean they have shown great promise in a variety of gas separation and water purification applications; are discussed. The aim is to draw links between the uses of MONs in these different applications in order to highlight the common opportunities and challenges presented by this promising class of nanomaterials.     

A mixed-field solution for scattering from composite bodies

The mixed-field solution combines different integral equations on different parts of a scatterer. It can be used for a variety of problems involving composite bodies. It is particularly useful on bodies having both "thin" and "thick" parts, It also appears capable of providing a good approximation to scattering from discontinuous surface-impedance distributions.     

The graph search machine (GSM): A VLSI architecture for connected speech recognition and other applications

A programmable VLSI architecture is described for efficiently computing a variety of kernel operations for speech recognition. These operations include dynamic programming for isolated and connected word recognition using both the template matching approach and the Hidden Markov Model (HMM) approach, the use of finite-state grammars (FSG) for connected word recognition, and metric computations for vector quantization and distance measurement. These are collectively referred to as "graph search" operations since a diagram consisting of arcs and nodes is commonly used to illustrate the HMM or FSG. As well as being able to efficiently compute a wide class of speech processing operations, the architecture is useful in other areas such as image processing. A chip design has been completed using 1.75-µm CMOS design rules and combines both custom and standard cell aproaches.     

Ultra-Robust Flexible Electronics by Laser-Driven Polymer-Nanomaterials Integration

Polyethylene terephthalate (PET) is the most widely used polymer in the world. For the first time, the laser-driven integration of aluminum nanoparticles (Al NPs) into PET to realize a laser-induced graphene/Al NPs/polymer composite, which demonstrates excellent toughness and high electrical conductivity with the formation of aluminum carbide into the polymer is shown. The conductive structures show an impressive mechanical resistance against >10000 bending cycles, projectile impact, hammering, abrasion, and structural and chemical stability when in contact with different solvents (ethanol, water, and aqueous electrolytes). Devices including thermal heaters, carbon electrodes for energy storage, electrochemical and bending sensors show this technology's practical application for ultra-robust polymer electronics. This laser-based technology can be extended to integrating other nanomaterials and create hybrid graphene-based structures with excellent properties in a wide range of flexible electronics’ applications.     

High-frequency fields excited by truncated arrays of nonuniformlydistributed filamentary scatterers on an infinite dielectric slab:parameterizing (leaky mode)-(Floquet mode) interaction

In previous studies, we have developed and tested observable-based parameterizations (OBP) of time-harmonic wavefield scattering by periodic or aperiodic finite arrays of planar strip and filament scatterers. The resulting algorithm is based on truncated Floquet modes and Floquet-modulated edge diffractions due to the truncations of the array. The corresponding robust wave processes link features (observables) in scattering data with geometrical features in the model configuration in such a manner as to be useful for subsequent application to target classification and identification. The present study extends these investigations to a finite array of filamentary scatterers located on the surface of an infinitely extended dielectric slab, thereby parameterizing (Floquet mode)-(leaky mode) interaction as a classifier of the more complicated phenomenology in this composite configuration. The outcome is an OBP with two separate constituents that can be interpreted, respectively, as slab-modified Floquet scattering by the truncated array and as truncated-Floquet-induced excitation of slab-guided leaky waves. This new OBP for the composite problem is validated by comparison with reference solutions generated numerically, its relevance to wave-oriented data processing is demonstrated in the companion paper     

Signal processing and the World Wide Web

The World Wide Web offers much information useful to the signal processing community. Using the Web, information having a variety of different forms can be transferred in a cohesive fashion. The article describes the rudiments of accessing the Web and how to create your own information resources. The authors focus on signal processing resources and how the Web catalyzes signal processing research and development     

The Next Frontier in Melt Electrospinning: Taming the Jet

There is a specialized niche for the electrohydrodynamic jetting of melts, from biomedical products to filtration and soft matter applications. The next frontier includes optics, microfluidics, flexible electronic devices, and soft network composites in biomaterial science and soft robotics. The recent emphasis on reproducibly direct‐writing continual molten jets has enabled a spectrum of contemporary microscale 3D objects to be fabricated. One strong suit of melt processing is the capacity for the jet to solidify rapidly into a fiber, thus fixing a particular structure into position. The ability to direct‐write complex and multiscaled architectures and structures has greatly contributed to a large number of recent studies, explicitly, toward fiber–hydrogel composites and fugitive inks, and has expanded into several biomedical applications such as cartilage, skin, periosteum, and cardiovascular tissue engineering. Following the footsteps of a publication that summarized melt electrowriting literature up to 2015, the most recent literature from then until now is reviewed to provide a continuous and comprehensive timeline that demonstrates the latest advances as well as new perspectives for this emerging technology.     

Modeling the growth of PECVD silicon nitride films for solar cellapplications using neural networks

Silicon nitride films grown by plasma-enhanced chemical vapor deposition (PECVD) are useful for a variety of applications, including anti-reflection coatings in solar cells, passivation layers, dielectric layers in metal/insulator structures, and diffusion masks, PECVD nitride films are known to contain hydrogen, and defect passivation by hydrogenation enhances efficiency in polycrystalline silicon solar cells. PECVD systems are controlled by many operating variables, including RF power, pressure, gas flow rate, reactant composition, and substrate temperature. The wide variety of processing conditions, as well as the complex nature of particle dynamics within a plasma, makes tailoring Si₃N₄ film properties very challenging, since it is difficult to determine the exact relationship between desired film properties and controllable deposition conditions. In this study, silicon nitride PECVD modeling using neural networks has been investigated. The deposition of Si₃N₄ was characterized via a central composite experimental design, and data from this experiment was used to train optimized feed-forward neural networks using the back-propagation algorithm. From these neural process models, the effect of deposition conditions on film properties has been studied. It was found that the process parameters critical to increasing hydrogenation and therefore enhancing carrier lifetime in polysilicon solar cells are temperature, silane, and ammonia flow rate. The deposition experiments were carried out in a Plasma Therm 700 series PECVD system     

Qubit devices and the issue of quantum decoherence

The exciting new field of quantum information science and technology is burgeoning with revolutionary new advances in the areas of quantum communication, quantum information processing, quantum computing, and quantum cryptography. Potential useful products of these advances include a wide variety of innovative qubit devices, ranging from quantum games and quantum teleporters to quantum computers and quantum robots. The major obstacle to the successful development of these devices is the phenomenon of quantum decoherence. This brief survey article gives reviews of a full gamut of potential qubit devices, alternating with expository discussions of the issue of quantum decoherence as it relates to the possible practical development of these devices. The qubit devices examined here include an interaction-free detector, a quantum key receiver, quantum games, various quantum gates, qubit entanglers, quantum dense coders, Bell-state analyzers, entanglement swappers, quantum teleporters, quantum repeaters, entangled atomic clocks, quantum copiers, various quantum computers, and quantum robots.     

Colloid-Mediated Fabrication of a 3D Pollen Sponge for Oil Remediation Applications

There is tremendous interest in developing 3D scaffolds from natural materials for a wide range of healthcare, energy, photonic, and environmental science applications. To date, most natural materials that are used to make 3D scaffolds consist of fibril structures; however, it would be advantageous to explore the development of scaffolds from natural materials with distinct supramolecular structures. Herein, the fabrication of a mechanically responsive pollen sponge that exhibits tunable 3D scaffold properties and is useful for oil remediation applications is reported. By using pollen-based microgel particles as colloidal building blocks, the sponge fabrication process is optimized by tuning the processing conditions during freeze-drying and thermal annealing steps. Stearic acid functionalization transforms the pollen sponge into a hydrophobic scaffold that can readily and repeatedly absorb oil and other organic solvents from contaminated water sources, with similar performance levels to commercial, synthetic polymer-based absorbents and an improved environmental footprint.     

天然鲜胶乳制备蒙脱土/NR纳米复合材料的结构与性能

采用多溶剂分散法制备片层尺寸达微、纳米级蒙脱土,并与天然鲜胶乳混合制备蒙脱土/天然橡胶复合材料,用扫描电镜研究蒙脱土结构及其在复合材料中的分布,并测定其力学性能.结果表明,通过多溶剂分散法可制备片层厚度为100nm～200nm的蒙脱土;在蒙脱土填充量为7%时,复合材料500%定伸应力从6.96MPa提高到11.22MPa;加入2%蒙脱土,复合材料拉伸强度从17.71MPa提高到21.01MPa;在4%填充量下,拉伸强度达23.56MPa,体现蒙脱土纳米增强效应.材料扯断伸长率随蒙脱土填充量增加而下降的幅度小,复合材料保持高弹性.复合材料硬度在蒙脱土填充量为8%时达到稳定值.上述结果表明,天然鲜胶乳可与蒙脱土直接复合,制备高性能天然橡胶复合材料.     

Reconfigurable Filter Coprocessor Architecture for DSP Applications

Digital Signal Processing (DSP) is widely used in high-performance media processing and communication systems. In majority of these applications, critical DSP functions are realized as embedded cores to meet the low-power budget and high computational complexity. Usually these cores are ASICs that cannot be easily retargeted for other similar applications that share certain commonalities. This stretches the design cycle that affects time-to-market constraints. In this paper, we present a reconfigurable high-performance low-power filter coprocessor architecture for DSP applications. The coprocessor architecture, apart from having the performance and power advantage of its ASIC counterpart, can be reconfigured to support a wide variety of filtering computations. Since filtering computations abound in DSP applications, the implementation of this coprocessor architecture can serve as an important embedded hardware IP.     

光电综合光缆有关问题的探讨

光电综合光缆的结构复杂多样、应用广泛。对光电综合光缆的产品名称、设计要求、试验方法及标准化建设方面的一些基本问题进行探讨,以期对光电综合光缆的研制有一定的参考作用。     

沉积在聚合物表面上的金属薄膜自发形成图案的实验研究

用离子溅射法在聚二甲基硅氧（polydimethylsiloxane,PDMS）表面沉积的金膜因金属与聚合物之间热膨胀系数的差异从而导致了具有正弦界面、微米尺度的波长和振幅的复杂而有序的褶皱图案。用光刘技术在硅片制备图形结构作为模板,通过复制模铸得到表面具有浮雕结构的聚二甲基硅氧烷基片。改变浮雕结构可以调控其上沉积的金膜的褶皱图案呈规则有序的排列。这种多尺度的复合结构将光刘技术、复制模铸和物理自组装等有效结合,可广泛应用于微纳制造领域。     

Robot-Vision Signal Processing Primitives

Recent advances in vision algorithms and increases in computer performance have made new capabilities available in autonomous robotics for real-time applications. In general, computer-vision-based solutions to robotics problems employ a high-level system architecture that makes use of low-level processing blocks. While the high-level system architecture is still an active area of research, many of the underlying low-level processing blocks and their associated methods have begun to stabilize, yielding a set of operators that has been found useful in a wide variety of tasks. In this article, we will briefly review these operators, which we call robot-vision signal-processing (SP) primitives, and their associated classes of methods. Although our taxonomy is quite general and related to those used in image processing and pattern recognition, we focus on the specific use of these primitives and associated classes in robot vision for SP purposes before presenting a robot-vision example- the Stanley robot racing car.     

Core-shell Pd nanoparticles embedded in SnOx films. Synthesis, analytical characterisation and perspective application in chemiresistor-type sensing devices

A two-step bottom up preparation protocol is proposed as a useful tool for the controlled modification of tin oxide films by means of Pd nanoparticles (PdNPs). Colloidal palladium is prepared via an electrolytic process that affords for a core-shell particle structure, while nanostructured tin oxide films are prepared following a sol–gel process. Pd/SnO_x composite layers are obtained adding a proper aliquot of pre-formed PdNPs to the tin oxide precursor solution. The nanomaterials surface chemical composition is addressed by X-ray Photoelectron Spectroscopy. Preliminary results on the application of Pd/SnO_x as active layers in chemiresistor-type gas-sensing devices are reported, as well.     

One‐Step Multipurpose Surface Functionalization by Adhesive Catecholamine

Surface modification is one of the most important techniques in modern science and engineering. The facile introduction of a wide variety of desired properties onto virtually any material surface is an ultimate goal in surface chemistry. To achieve this goal, the incorporation of structurally diverse molecules onto any material surface is an essential capability for ideal surface modification. Here, a general strategy for surface modification is presented in which many diverse surfaces can be functionalized by immobilizing a wide variety of molecules. This strategy functionalizes surfaces by a one‐step immersion of substrates in a one‐pot mixture of a molecule and a catecholamine surface modification agent. This one‐step procedure for surface modification represents a standard protocol to control interfacial properties.     

Parameter optimisation modeling using stationary 1D-electrothermal model to improve temperature homogeneity.

A parameter optimisation model is developed to find the parameters that have significant effects on homogeneous temperature distribution during microwave processing of materials. Electromagnetic, thermal and processing parameters are collected for a wide variety of materials and the heating profiles are calculated using a stationary 1D-electrothermal model. A measure of temperature homogeneity is obtained from the heating profiles by statistical calculations of normalised variance (the response variable). The processing parameters (power, temperature, size of the material sample) are optimisedfor all of these materials for a minimum normalised variance which allows maximum change of +/-3% Taverage on the T-distribution to meet most of the industrial process requirements. This mathematical model suggests a group of materials, which requires modifications in processing conditions to achieve uniform heating.