UV‐Triggered Polymerization,Deposition, and Patterning of Plant Phenolic Compounds

Plant‐derived phenolic compounds, rich in catechol and pyrogallol moieties, can form multifunctional coatings on various substrates following polymerization under mildly alkaline conditions. Despite many appealing features of such coatings, the difficulty to control polymerization of phenolic compounds spatially and temporally limits their number of potential applications. In this study, it is demonstrated that UV irradiation can trigger oxidative polymerization and deposition of plant‐derived phenolic compounds, which opens the possibility to create 2D gradients and patterns of polyphenol coatings and control this polymerization temporally. UV–vis spectroscopy, electrospray ionization mass spectrometry, and cyclic voltammetry analyses are used to investigate the UV‐induced polymerization of several plant‐derived phenolic compounds including pyrogallol, tannic acid, caffeic acid, and gallic acid. Formation of polyphenol coatings on polar and nonpolar substrates after UV irradiation has been studied using water contact angle measurements, atomic force microscopy, time of flight secondary ion mass spectrometry, and X‐ray photoelectron spectroscopy (XPS). The possibility to use UV‐light to accelerate polymerization of phenolic compounds and perform micropatterning can extend the scope of potential applications of the large class of structurally diverse plant‐derived phenolic compounds.     

用LED寻找故障的电缆测试仪

本例描述了一个简单的电缆测试仪,它能形象地显示出一根16线电缆束(用于超声辅助驻车系统)的通断问题。一家承包商小批量地生产该线束,因此不适合采用自动化测试仪。为简单起见,用测试信号驱动几只LED,形象化地表示出通断情况。图1中的电路产生一个从0至15的二进制数(0000至1111)。可     

Transient thermo-reflectance measurements of the thermal conductivity and interface resistance of metallized natural and isotopically-pure silicon

The transient thermoreflectance method has been used to measure the thermal conductivity of natural silicon and isotopically-pure silicon-28 layers that are epitaxially grown on natural silicon substrates. The measurements were performed at room temperature for both a low level (10¹⁶) and a higher level (2×10¹⁹) of Boron doping of the epitaxial layers. The results indicate a gain of approximately 55% in the thermal conductivity of Si²⁸ as compared to that of natural Si, at both low and higher levels of doping, and a loss of approximately 19% for both types of silicon due to the higher level of doping.     

Applying Petri Nets to Modeling of Many-Core Processor Self-Testing when Tests are Performed Randomly

Today’s many-core processors are manufactured in inherently unreliable technologies. Massively defective technologies used for production of many-core processors are the direct consequence of the feature size shrinkage in today’s CMOS (complementary metal-oxide-semiconductor) technology. Due to these reliability problems, fault-tolerance of many-core processors becomes one of the major challenges. To reduce the probability of failures of many-core processors various fault tolerance techniques can be applied. The most preferable and promising techniques are the ones that can be easily implemented and have minimal cost while providing high level of processor fault tolerance. One of the promising techniques for detection of faulty cores, and consequently, for performing the first step in providing many-core processor fault tolerance is mutual testing among processor cores. Mutual testing can be performed either in a random manner or according to a deterministic scheduling policy. In the paper we deal with random execution of mutual tests. Effectiveness of such testing can be evaluated through its modeling. In the paper, we have shown how Stochastic Petri Nets can be used for this purpose and have obtained some results that can be useful for developing and implementation of testing procedure in many-core processors.     

In Situ Liquid-Cell TEM Observation of Multiphase Classical and Nonclassical Nucleation of Calcium Oxalate

Calcium oxalate (CaOx) is the major phase in kidney stones and the primary calcium storage medium in plants. CaOx can form crystals with different lattice types, water contents, and crystal structures. However, the conditions and mechanisms leading to nucleation of particular CaOx crystals are unclear. Here, liquid-cell transmission electron microscopy and atomistic molecular dynamics simulations are used to study in situ CaOx nucleation at different conditions. The observations reveal that rhombohedral CaOx monohydrate (COM) can nucleate via a classical pathway, while square COM can nucleate via a non-classical multiphase pathway. Citrate, a kidney stone inhibitor, increases the solubility of calcium by forming calcium-citrate complexes and blocks oxalate ions from approaching calcium. The presence of multiple hydrated ionic species draws additional water molecules into nucleating CaOx dihydrate crystals. These findings reveal that by controlling the nucleation pathways one can determine the macroscale crystal structure, hydration state, and morphology of CaOx.     

Thermoelectric Effect Spectroscopy and Photoluminescence of High-Resistivity CdTe:In

Thermoelectric effect spectroscopy and photoluminescence techniques were used to study the defect levels in samples from three crystals of CdTe:In grown by the vertical gradient freeze method. The main goal of the investigation was to study defects, which strongly trap charge carriers or act as recombination centers in order to eliminate them from the technological process. The main difference among detecting and non-detecting samples was the absence of electron traps with a very high capture cross-section and energy 0.6 eV to 0.7 eV, which act as lifetime killers even at low concentrations. Recently published ab initio calculations show a complex of Te antisite and Cd vacancy within this energy range.     

Substrate-Independent and Re-Writable Surface Patterning by Combining Polydopamine Coatings,Silanization, and Thiol-Ene Reaction

Polydopamine coating is a unique, simple, and substrate-independent surface functionalization strategy. Techniques for secondary functionalization, patterning, and re-functionalization of polydopamine modified materials are important to broaden the scope of applications of such materials in a variety of fields. Here, a facile and substrate-independent strategy for surface functionalization and patterning is presented. This approach combines the advantages of three important methods: facile and substrate-independent polydopamine coating, versatile gas phase silanization, and rapid thiol-ene photoclick reaction for patterning. They demonstrate equally efficient functionalization and patterning of diverse materials, such as glass, polytetrafluoroethylene, aluminum, polypropylene, or polyethylene. They also show the possibility of controlled chemical removal of the patterns or surface functionalization by treatment with tetrabutylammonium fluoride, which allows re-modification or re-patterning of the substrate. Thus, this universal and powerful approach for substrate independent surface modification and patterning can significantly facilitate the development of novel functional materials and devices useful for various applications.     

Controlling a Semiconductor Optical Amplifier Using a State-Space Model

We derive nonlinear and linear state-space control models for a multichannel semiconductor optical amplifier. Verified against the governing partial differential equations through simulation, the linear model tracks modulations up to 20% qualitatively well. Linear feedback control is then employed to design two interchannel crosstalk suppressing systems, one using state feedback into the electronic drive current and the other using optical output feedback into an optical control channel; the controller designed with the linear model is seen to work well even with 100% modulations of the nonlinear system. This linear state-space model opens the way for further robust analysis, design and control of integrated active photonic circuits     

0.18μm铜金属双重镶嵌工艺中空间成像套刻精度分析

由于空间成像套刻(Overlay)技术的预算随集成电路(IC)设计规范的紧缩而吃紧,因此,Overlay测量技术准确度的重要意义也随之提高。通过对后开发(AfterDevelopDI)阶段和后蚀刻(AfterEtchFI)阶段的Overlay测量结果进行比较,研究了0.18μm设计规范下的铜金属双重镶嵌工艺过程中的Overlay准确度。在确保对同一个晶圆进行后开发(DI)阶段和后蚀刻(FI)阶段测试的条件下,我们对成品晶圆的5个工艺层进行了比较。此外,还利用CD-SEM(线宽-扫描电子显微镜)测量了某个工艺层(PolyGate)上的芯片内Overlay,并与采用分割线方法的光学Overlay测量结果进行了比较。发现对芯片内overlay的校准存在着严重的局限性,即在应用CD-SEM时缺乏合适的结构进行Overlay测量。我们还将继续为大家提供定量的比较结果,同时也会向大家推荐组合的CD-SEM测量结构,使其能够被应用到今后的光刻设计中。