Showing papers by "National Tsing Hua University published in 2015"
TL;DR: In this paper, the authors review the performance of the LIGO instruments during this epoch, the work done to characterize the detectors and their data, and the effect that transient and continuous noise artefacts have on the sensitivity of the detectors to a variety of astrophysical sources.
Abstract: In 2009–2010, the Laser Interferometer Gravitational-Wave Observatory (LIGO) operated together with international partners Virgo and GEO600 as a network to search for gravitational waves (GWs) of astrophysical origin. The sensitivity of these detectors was limited by a combination of noise sources inherent to the instrumental design and its environment, often localized in time or frequency, that couple into the GW readout. Here we review the performance of the LIGO instruments during this epoch, the work done to characterize the detectors and their data, and the effect that transient and continuous noise artefacts have on the sensitivity of LIGO to a variety of astrophysical sources.
1,266 citations
TL;DR: In this article, microcavity polaritons were observed in a dielectric cavity containing a monolayer of molybdenum disulphide at room temperature.
Abstract: Microcavity polaritons—the bosonic quasiparticles that result from strong light–matter coupling—are observed for the first time in a dielectric cavity containing a monolayer of molybdenum disulphide at room temperature.
967 citations
TL;DR: It is demonstrated that a photodetector based on the graphene/MoS2 heterostructure is able to provide a high photogain greater than 108 and graphene is transferable onto MoS2.
Abstract: Due to its high carrier mobility, broadband absorption, and fast response time, the semi-metallic graphene is attractive for optoelectronics. Another two-dimensional semiconducting material molybdenum disulfide (MoS2) is also known as light- sensitive. Here we show that a large-area and continuous MoS2 monolayer is achievable using a CVD method and graphene is transferable onto MoS2. We demonstrate that a photodetector based on the graphene/MoS2 heterostructure is able to provide a high photogain greater than 10(8). Our experiments show that the electron-hole pairs are produced in the MoS2 layer after light absorption and subsequently separated across the layers. Contradictory to the expectation based on the conventional built-in electric field model for metal-semiconductor contacts, photoelectrons are injected into the graphene layer rather than trapped in MoS2 due to the presence of a perpendicular effective electric field caused by the combination of the built-in electric field, the applied electrostatic field, and charged impurities or adsorbates, resulting in a tuneable photoresponsivity.
831 citations
TL;DR: In this article, the Weyl semimetal state in an inversion-symmetry-breaking single-crystalline solid, Niobium arsenide (NbAs), has been discovered.
Abstract: Three types of fermions play a fundamental role in our understanding of nature: Dirac, Majorana and Weyl. Whereas Dirac fermions have been known for decades, the latter two have not been observed as any fundamental particle in high-energy physics, and have emerged as a much-sought-out treasure in condensed matter physics. A Weyl semimetal is a novel crystal whose low-energy electronic excitations behave as Weyl fermions. It has received worldwide interest and is believed to open the next era of condensed matter physics after graphene and three-dimensional topological insulators. However, experimental research has been held back because Weyl semimetals are extremely rare in nature. Here, we present the experimental discovery of the Weyl semimetal state in an inversion-symmetry-breaking single-crystalline solid, niobium arsenide (NbAs). Utilizing the combination of soft X-ray and ultraviolet photoemission spectroscopy, we systematically study both the surface and bulk electronic structure of NbAs. We experimentally observe both the Weyl cones in the bulk and the Fermi arcs on the surface of this system. Our ARPES data, in agreement with our theoretical band structure calculations, identify the Weyl semimetal state in NbAs, which provides a real platform to test the potential of Weyltronics. Experiments show that niobium arsenide is a Weyl semimetal.
754 citations
TL;DR: Because catalase is immobilized and sheltered by the ZIF-90 crystals, the composites show activity in hydrogen peroxide degradation even in the presence of protease proteinase K.
Abstract: We develop a new concept to impart new functions to biocatalysts by combining enzymes and metal–organic frameworks (MOFs). The proof-of-concept design is demonstrated by embedding catalase molecules into uniformly sized ZIF-90 crystals via a de novo approach. We have carried out electron microscopy, X-ray diffraction, nitrogen sorption, electrophoresis, thermogravimetric analysis, and confocal microscopy to confirm that the ∼10 nm catalase molecules are embedded in 2 μm single-crystalline ZIF-90 crystals with ∼5 wt % loading. Because catalase is immobilized and sheltered by the ZIF-90 crystals, the composites show activity in hydrogen peroxide degradation even in the presence of protease proteinase K.
620 citations
TL;DR: This work experimentally demonstrate interlayer band-to-band tunneling in vertical MoS2/WSe2 van der Waals (vdW) heterostructures using a dual-gate device architecture with important implications toward the design of atomically thin tunnel transistors.
Abstract: Two-dimensional layered semiconductors present a promising material platform for band-to-band-tunneling devices given their homogeneous band edge steepness due to their atomically flat thickness. Here, we experimentally demonstrate interlayer band-to-band tunneling in vertical MoS2/WSe2 van der Waals (vdW) heterostructures using a dual-gate device architecture. The electric potential and carrier concentration of MoS2 and WSe2 layers are independently controlled by the two symmetric gates. The same device can be gate modulated to behave as either an Esaki diode with negative differential resistance, a backward diode with large reverse bias tunneling current, or a forward rectifying diode with low reverse bias current. Notably, a high gate coupling efficiency of ∼80% is obtained for tuning the interlayer band alignments, arising from weak electrostatic screening by the atomically thin layers. This work presents an advance in the fundamental understanding of the interlayer coupling and electron tunneling in ...
556 citations
TL;DR: In this paper, angle-resolved photoemission spectroscopy was used to experimentally observe a pair of spin-polarized Fermi arc surface states on the surface of the Dirac semimetal Na3Bi at its native chemical potential.
Abstract: The topology of the electronic structure of a crystal is manifested in its surface states. Recently, a distinct topological state has been proposed in metals or semimetals whose spin-orbit band structure features three-dimensional Dirac quasiparticles. We used angle-resolved photoemission spectroscopy to experimentally observe a pair of spin-polarized Fermi arc surface states on the surface of the Dirac semimetal Na3Bi at its native chemical potential. Our systematic results collectively identify a topological phase in a gapless material. The observed Fermi arc surface states open research frontiers in fundamental physics and possibly in spintronics.
537 citations
TL;DR: In this article, the efficiency records of OLED devices using fluorescent, phosphorescent, and thermally activated delay fluorescent materials are summarized and a review of all the available efficiency-effective device architectural approaches, which include using thin layer structures, low carrier injection barriers, high carrier mobility, balanced carrier injection, effective carrier confinement, effective host-to-guest energy transfer, effective recombination zone, effective exciton generation on the host and p-i-n structures, and tandem structures.
Abstract: Efficiency is crucial for organic light emitting diodes (OLEDs) to be energy-saving and to have a long lifetime for display and solid state lighting applications. Numerous approaches have been proposed to attain high efficiency OLEDs through the synthesis of novel organic materials, the design of light extraction structures and the design of efficiency-effective device architectures. In this report, we first summarise the efficiency records of OLED devices using fluorescent, phosphorescent, and thermally activated delay fluorescent materials. Importantly, we review all the available efficiency-effective device architectural approaches, which include using thin layer structures, low carrier injection barriers, high carrier mobility, balanced carrier injection, effective carrier confinement, effective host-to-guest energy transfer, effective recombination zone, effective exciton generation on the host, effective exciton confinement, p–i–n structures, and tandem structures. It is hoped that better device structures can therefore be devised upon suitable device engineering to achieve higher efficiency for OLED devices.
507 citations
TL;DR: This review discusses the key challenges to the development of the carriers for miRNA-based therapy and explores current strategies to systemically deliver miRNAs to cancer without induction of toxicity.
503 citations
TL;DR: High efficiency and stable inverted PSCs (i-PSC) are presented by employing sol-gel processed simultaneously doped ZnO by Indium and fullerene derivative (BisNPC60-OH) film as cathode interlayer and PTB7-Th:PC71BM as the active layer.
Abstract: We present high efficiency and stable inverted PSCs (i-PSC) by employing sol-gel processed simultaneously doped ZnO by Indium and fullerene derivative (BisNPC60-OH) (denoted as InZnO-BisC60) film as cathode interlayer and PTB7-Th:PC71BM as the active layer (where PTB7-Th is a low bandgap polymer we proposed previously). This dual-doped ZnO, InZnO-BisC60, film shows dual and opposite gradient dopant concentration profiles, being rich in fullerene derivative at the cathode surface in contact with active layer and rich in In at the cathode surface in contact with the ITO surface. Such doping in ZnO not only gives improved surface conductivity by a factor of 270 (from 0.015 to 4.06 S cm−1) but also provides enhanced electron mobility by a factor of 132 (from 8.25*10−5 to 1.09*10−2 cm2 V−1 s−1). The resulting i-PSC exhibits the improved PCE 10.31% relative to that with ZnO without doping 8.25%. This PCE 10.31% is the best result among the reported values so far for single junction PSC.
482 citations
TL;DR: In this article, the composition of HfNbTaTiZr was modified with an aim to improve its strength at high temperature, while retaining reasonable toughness at room temperature.
Journal Article•
TL;DR: By applying intense circularly polarized light, which breaks time-reversal symmetry, it is demonstrated that the exciton level in each valley can be selectively tuned by as much as 18 meV through the optical Stark effect, which offers a new way to control the valley degree of freedom.
Abstract: Breaking space-time symmetries in two-dimensional crystals (2D) can dramatically influence their macroscopic electronic properties. Monolayer transition metal dichalcogenides (TMDs) are prime examples where the intrinsically broken crystal inversion symmetry permits the generation of valley-selective electron populations [1–4], even though the two valleys are energetically degenerate, locked by time-reversal symmetry. Lifting the valley degeneracy in these materials is of great interest because it would allow for valley-specific band engineering and offer additional control in valleytronic applications. While applying a magnetic field should in principle accomplish this task, experiments to date have observed no valley-selective energy level shifts in fields accessible in the laboratory. Here we show the first direct evidence of lifted valley degeneracy in the monolayer TMD WS2 [5]. By applying intense circularly polarized light, which breaks time-reversal symmetry, we demonstrate that the exciton level in each valley can be selectively tuned by as much as 18 meV via the optical Stark effect. These results offer a novel way to control valley degree of freedom and may provide a means to realize new valley-selective Floquet topological phases [6–8] in 2D TMDs.
TL;DR: In this article, the authors show that lifted valley degeneracy in 2D transition metal dichalcogenides (TMDs) can be lifted by applying intense circularly polarized light, which breaks time-reversal symmetry, and demonstrate that the exciton level in each valley can be selectively tuned by as much as 18 meV via the optical Stark effect.
Abstract: Breaking space-time symmetries in two-dimensional crystals (2D) can dramatically influence their macroscopic electronic properties. Monolayer transition metal dichalcogenides (TMDs) are prime examples where the intrinsically broken crystal inversion symmetry permits the generation of valley-selective electron populations [1–4], even though the two valleys are energetically degenerate, locked by time-reversal symmetry. Lifting the valley degeneracy in these materials is of great interest because it would allow for valley-specific band engineering and offer additional control in valleytronic applications. While applying a magnetic field should in principle accomplish this task, experiments to date have observed no valley-selective energy level shifts in fields accessible in the laboratory. Here we show the first direct evidence of lifted valley degeneracy in the monolayer TMD WS2 [5]. By applying intense circularly polarized light, which breaks time-reversal symmetry, we demonstrate that the exciton level in each valley can be selectively tuned by as much as 18 meV via the optical Stark effect. These results offer a novel way to control valley degree of freedom and may provide a means to realize new valley-selective Floquet topological phases [6–8] in 2D TMDs.
TL;DR: It is shown that the direction of conducting channels in ReS2 and ReSe2 can be controlled by electron beam irradiation at elevated temperatures and follows the strain induced to the sample, which is strongly direction-dependent.
Abstract: Rhenium disulfide (ReS2) and diselenide (ReSe2), the group 7 transition metal dichalcogenides (TMDs), are known to have a layered atomic structure showing an in-plane motif of diamond-shaped-chains (DS-chains) arranged in parallel. Using a combination of transmission electron microscopy and transport measurements, we demonstrate here the direct correlation of electron transport anisotropy in single-layered ReS2 with the atomic orientation of the DS-chains, as also supported by our density functional theory calculations. We further show that the direction of conducting channels in ReS2 and ReSe2 can be controlled by electron beam irradiation at elevated temperatures and follows the strain induced to the sample. Furthermore, high chalcogen deficiency can induce a structural transformation to a nonstoichiometric phase, which is again strongly direction-dependent. This tunable in-plane transport behavior opens up great avenues for creating nanoelectronic circuits in 2D materials.
TL;DR: A special two-day international workshop on high-entropy alloys was held in Guiyang, China, in December 2014 as mentioned in this paper to discuss the scientific issues and challenges to foster international collaborations, and to identify future directions.
TL;DR: In this paper, the fatigue behavior of a cold-rolled two-phase Al0.5CoCrCuFeNi high-entropy alloy (HEA) was studied.
TL;DR: In this article, a Weyl semimetal was realized in TaP using photo-emission spectroscopy, and the surface states showed an unexpectedly rich structure, including both topological Fermi arcs and several topologically trivial closed contours in the vicinity of the Weyl points.
Abstract: Weyl semimetals are expected to open up new horizons in physics and materials science because they provide the first realization of Weyl fermions and exhibit protected Fermi arc surface states. However, they had been found to be extremely rare in nature. Recently, a family of compounds, consisting of tantalum arsenide, tantalum phosphide (TaP), niobium arsenide, and niobium phosphide, was predicted as a Weyl semimetal candidates. We experimentally realize a Weyl semimetal state in TaP. Using photoemission spectroscopy, we directly observe the Weyl fermion cones and nodes in the bulk, and the Fermi arcs on the surface. Moreover, we find that the surface states show an unexpectedly rich structure, including both topological Fermi arcs and several topologically trivial closed contours in the vicinity of the Weyl points, which provides a promising platform to study the interplay between topological and trivial surface states on a Weyl semimetal’s surface. We directly demonstrate the bulk-boundary correspondence and establish the topologically nontrivial nature of the Weyl semimetal state in TaP, by resolving the net number of chiral edge modes on a closed path that encloses the Weyl node. This also provides, for the first time, an experimentally practical approach to demonstrating a bulk Weyl fermion from a surface state dispersion measured in photoemission.
TL;DR: The method offers a controllable synthesis to obtain high-quality in-plane heterostructures of TMD atomic layers with 1D interface geometry and it is found that the one-dimensinal (1D) interface of the lateral heterostructure picks the zigzag direction of the lattice instead of the armchair direction.
Abstract: Atomically thin heterostructures of transition-metal dichalcogenides (TMDs) with various geometrical and energy band alignments are the key materials for next generation flexible nanoelectronics. The individual TMD monolayers can be adjoined laterally to construct in-plane heterostructures, which are difficult to reach with the laborious pick-up-and-transfer method of the exfoliated flakes. The ability to produce copious amounts of high quality layered heterostructures on diverse surfaces is highly desirable but it has remained a challenging issue. Here, we have achieved a direct synthesis of lateral heterostructures of monolayer TMDs: MoS2–WS2 and MoSe2–WSe2. The synthesis was performed using ambient-pressure chemical vapor deposition (CVD) with aromatic molecules as seeding promoters. We discuss possible growth behaviors, and we examine the symmetry and the interface of these heterostructures using second-harmonic generation and atomic-resolution scanning TEM. We found that the one-dimensinal (1D) inter...
TL;DR: The macroscopic and microscopic data conclusively identified the formation of inner-sphere complexes between As and MNP surfaces and complex redox transformation of the adsorbed As on MNPs exposed to air was revealed.
Abstract: Removal of arsenic (As) from water supplies is needed to reduce As exposure through drinking water and food consumption in many regions of the world. Magnetite nanoparticles (MNPs) are promising and novel adsorbents for As removal because of their great adsorption capacity for As and easy separation. This study aimed to investigate the adsorption mechanism of arsenate, As(V), and arsenite, As(III), on MNPs by macroscopic adsorption experiments in combination with thermodynamic calculation and microspectroscopic characterization using synchrotron-radiation-based X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS). Adsorption reactions are favorable endothermic processes as evidenced by increased adsorption with increasing temperatures, and high positive enthalpy change. EXAFS spectra suggested predominant formation of bidentate binuclear corner-sharing complexes (2C) for As(V), and tridentate hexanuclear corner-sharing (3C) complexes for As(III) on MNP surfaces. The macroscopic a...
TL;DR: This work developed a chemical vapor deposition synthesis to produce large-area, uniform, and highly crystalline few-layer 2H and 1T' MoTe2 films, and found that these two different phases ofMoTe2 can be grown depending on the choice of Mo precursor.
Abstract: The controlled synthesis of large-area, atomically thin molybdenum ditelluride (MoTe2) crystals is crucial for its various applications based on the attractive properties of this emerging material. In this work, we developed a chemical vapor deposition synthesis to produce large-area, uniform, and highly crystalline few-layer 2H and 1T′ MoTe2 films. It was found that these two different phases of MoTe2 can be grown depending on the choice of Mo precursor. Because of the highly crystalline structure, the as-grown few-layer 2H MoTe2 films display electronic properties that are comparable to those of mechanically exfoliated MoTe2 flakes. Our growth method paves the way for the large-scale application of MoTe2 in high-performance nanoelectronics and optoelectronics.
TL;DR: Alkanethiolate ligand-regulated silver (Ag) nanoparticle films can be used to achieve quantitative SERS measurements down to the single-molecule level by measuring the areal densities of crystal violet molecules embedded in an ultrathin spin-on-glass detection "hot zone".
Abstract: Quantitative surface enhanced Raman spectroscopy (SERS) requires precise control of Raman enhancement factor and detection uniformity across the SERS substrate. Here, we show that alkanethiolate ligand-regulated silver (Ag) nanoparticle films can be used to achieve quantitative SERS measurements down to the single-molecule level. The two-dimensional hexagonal close-packed superlattices of Ag nanoparticles formed in these films allow for SERS detection over a large area with excellent uniformity and high Raman enhancement factor. In particular, the SERS signal from the thiolate ligands on Ag nanoparticle surfaces can be utilized as a stable internal calibration standard for reproducible quantitative measurements. We demonstrate the capability of quantitative SERS by measuring the areal densities of crystal violet molecules embedded in an ultrathin spin-on-glass detection “hot zone”, which is a planar and uniformly enhanced region several nanometers above the Ag nanoparticles. The Raman measurement results ...
TL;DR: In this article, two definitions of high-entropy alloys (HEAs), based on composition and entropy, are reviewed and four core effects, i.e., high entropy, sluggish diffusion, severe lattice distortion, and cocktail effects, are mentioned to show the uniqueness of HEAs.
Abstract: Two definitions of high-entropy alloys (HEAs), based on composition and entropy, are reviewed. Four core effects, i.e., high entropy, sluggish diffusion, severe lattice distortion, and cocktail effects, are mentioned to show the uniqueness of HEAs. The current state of physical metallurgy is discussed. As the compositions of HEAs are entirely different from that of conventional alloys, physical metallurgy principles might need to be modified for HEAs. The thermodynamics, kinetics, structure, and properties of HEAs are briefly discussed relating with the four core effects of HEAs. Among these, a severe lattice distortion effect is particularly emphasized because it exerts direct and indirect influences on many aspects of microstructure and properties. Because a constituent phase in HEAs can be regarded as a whole-solute matrix, every lattice site in the matrix has atomic-scale lattice distortion. In such a distorted lattice, point defects, line defects, and planar defects are different from those in conventional matrices in terms of atomic configuration, defect energy, and dynamic behavior. As a result, mechanical and physical properties are significantly influenced by such a distortion. Suitable mechanisms and theories correlating composition, microstructure, and properties for HEAs are required to be built in the future. Only these understandings make it possible to complete the physical metallurgy of the alloy world.
TL;DR: This paper presents origami triboelectric nanogenerators (TENGs) using paper as the starting material, with a high degree of flexibility, light weight, low cost, and recyclability, and can also serve as self-powered pressure sensors.
Abstract: Discovering renewable and sustainable power sources is indispensable for the development of green electronics and sensor networks. In this paper, we present origami triboelectric nanogenerators (TENGs) using paper as the starting material, with a high degree of flexibility, light weight, low cost, and recyclability. Slinky- and doodlebug-shaped TENGs can be easily fabricated by properly folding printer papers. The as-fabricated TENGs are capable of harvesting ambient mechanical energy from various kinds of human motions, such as stretching, lifting, and twisting. The generated electric outputs have been used to directly light-up commercial LEDs. In addition, the as-fabricated TENGs can also serve as self-powered pressure sensors.
TL;DR: Review of various optical inspection approaches in the semiconductor industry and categorize the previous literatures by the inspection algorithm and inspected products to achieve a high robustness and computational efficiency of automated visual inspection.
TL;DR: In this article, the optical constants of a CH3NH3PbI3−xClx perovskite thin film were acquired for the first time and detailed optical modelling and optimization were performed and the calculations suggest that power conversion efficiencies of up to 20% and 29% are feasible in planar-type single and tandem cells.
Abstract: The optical constants of a CH3NH3PbI3−xClx perovskite thin film were acquired for the first time. With this optical constant information, detailed optical modelling and optimization were performed and the calculations suggest that power conversion efficiencies of up to 20% and 29% are feasible in planar-type single and tandem cells.
TL;DR: In this article, a search for narrow resonances decaying into WW, WZ, or ZZ boson pairs using 20.3 fb(-1) of proton-proton collision data at a center-of-mass energy of root s = TeV recorded with the AT...
Abstract: A search is performed for narrow resonances decaying into WW, WZ, or ZZ boson pairs using 20.3 fb(-1) of proton-proton collision data at a centre-of-mass energy of root s = TeV recorded with the AT ...
TL;DR: The obtained results suggest the as-synthesized PSAC/Co3O4 is more suitable for the nonenzymatic glucose sensor and supercapacitor applications outperforming the related carbon based modified electrodes, rendering practical industrial applications.
Abstract: Herein, we report the preparation of Pongam seed shells-derived activated carbon and cobalt oxide (∼2–10 nm) nanocomposite (PSAC/Co3O4) by using a general and facile synthesis strategy. The as-synthesized PSAC/Co3O4 samples were characterized by a variety of physicochemical techniques. The PSAC/Co3O4-modified electrode is employed in two different applications such as high performance nonenzymatic glucose sensor and supercapacitor. Remarkably, the fabricated glucose sensor is exhibited an ultrahigh sensitivity of 34.2 mA mM–1 cm–2 with a very low detection limit (21 nM) and long-term durability. The PSAC/Co3O4 modified stainless steel electrode possesses an appreciable specific capacitance and remarkable long-term cycling stability. The obtained results suggest the as-synthesized PSAC/Co3O4 is more suitable for the nonenzymatic glucose sensor and supercapacitor applications outperforming the related carbon based modified electrodes, rendering practical industrial applications.
TL;DR: The versatility and utility of cobalt catalysis in organic synthesis is demonstrated, including enantioselective reductive coupling of enones and alkynes, addition of organoboronic acids to aldeHydes, and the cyclization of 2-iodobenzoates with aldehydes.
Abstract: ConspectusOver the last three decades, transition-metal-catalyzed organic transformations have been shown to be extremely important in organic synthesis. However, most of the successful reactions are associated with noble metals, which are generally toxic, expensive, and less abundant. Therefore, we have focused on catalysis using the abundant first-row transition metals, specifically cobalt. In this Account, we demonstrate the potential of cobalt catalysis in organic synthesis as revealed by our research.We have developed many useful catalytic systems using cobalt complexes. Overall, they can be classified into several broad types of reactions, specifically [2 + 2 + 2] and [2 + 2] cycloadditions; enyne reductive coupling; reductive [3 + 2] cycloaddition of alkynes/allenes with enones; reductive coupling of alkyl iodides with alkenes; addition of organoboronic acids to alkynes, alkenes, or aldehydes; carbocyclization of o-iodoaryl ketones/aldehydes with alkynes/electron-deficient alkenes; coupling of thio...
TL;DR: Wang et al. as mentioned in this paper proposed a set of novel rotation and scale-invariant features for obtaining a reduced representation of wafer maps, which are crucial when employing WMFPR and WMSR to analyze large-scale data sets.
Abstract: Wafer maps can exhibit specific failure patterns that provide crucial details for assisting engineers in identifying the cause of wafer pattern failures. Conventional approaches of wafer map failure pattern recognition (WMFPR) and wafer map similarity ranking (WMSR) generally involve applying raw wafer map data (i.e., without performing feature extraction). However, because increasingly more sensor data are analyzed during semiconductor fabrication, currently used approaches can be inadequate in processing large-scale data sets. Therefore, a set of novel rotation- and scale-invariant features is proposed for obtaining a reduced representation of wafer maps. Such features are crucial when employing WMFPR and WMSR to analyze large-scale data sets. To validate the performance of the proposed system, the world’s largest publicly accessible data set of wafer maps was built, comprising 811 457 real-world wafer maps. The experimental results show that the proposed features and overall system can process large-scale data sets effectively and efficiently, thereby meeting the requirements of current semiconductor fabrication.
TL;DR: Evidence is found that indicates that the Trojan-horse mechanism really exists, and it could be explained that H2O2, a major intracellular reactive oxygen species (ROS), reacts with AgNPs to form more Ag (I).
Abstract: The so-called "Trojan-horse" mechanism, in which nanoparticles are internalized within cells and then release high levels of toxic ions, has been proposed as a behavior in the cellular uptake of Ag nanoparticles (AgNPs). While several reports claim to have proved this mechanism by measuring AgNPs and Ag ions (I) in cells, it cannot be fully proven without examining those two components in both intra- and extracellular media. In our study, we found that even though cells take up AgNPs similarly to (microglia (BV-2)) or more rapidly than (astrocyte (ALT)) Ag (I), the ratio of AgNPs to total Ag (AgNPs+Ag (I)) in both cells was lower than that in outside media. It could be explained that H2O2, a major intracellular reactive oxygen species (ROS), reacts with AgNPs to form more Ag (I). Moreover, the major speciation of Ag (I) in cells was Ag(cysteine) and Ag(cysteine)2, indicating the possible binding of monomer cysteine or vital thiol proteins/peptides to Ag ions. Evidence we found indicates that the Trojan-horse mechanism really exists.