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Shock wave induced enhancement of optical properties of benzil crystal
摘要： In this article, we present the results of the experimental work on the impact of shock waves on optical properties of benzyl crystalline material. Test material of benzil crystal is grown along [100] plane by Sankaranarayana - Ramasamy method. In the present work, the functional shock waves of Mach number 1.7 are generated from pressure driven shock tube. The optical properties of test material are investigated by UV-Visible spectrometer over the range between 200 and 800nm. The observed results show that the intensity of the absorption spectrum is inversely proportional to the number of exposed shock waves. The direct and indirect optical band gap energy (Eg) and Urbach tail energy (Ug) are determined from the optical absorption spectrum for pre and post shock wave loaded condition and found that shock wave loaded test crystal has high band gap energy. The optical constants namely extinction coefficient, real and imaginary parts of the dielectric constant, skin depth, optical density, optical conductivity and electrical conductivity are investigated and the obtained results are compared with post shock wave loaded benzil crystal with the incident light possessing wavelength at 700 nm. The results are found to be very impressive for the shock wave recovery experiments that are to be clearly discussed.
关键词： Transmission,Shock Waves,Re-crystallization,Benzil crystal,Optical properties
更新于2025-09-23 15:23:52
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A novel on-line electrochemical transmission infrared spectroscopy to?study the current efficiency of carbonates for?ethanol oxidation reactions in alkaline media
摘要： Research on the reaction mechanism of ethanol oxidation reaction (EOR) is important for the development of highly active EOR electro-catalysts. One of the main difficulties in the EOR study is the quantitative analysis of the non-volatile products. Conventional on-line electrochemical flowing transmission infrared spectroscopy (ETIRS) can only collect a part of the carbonate products of EOR in alkaline media, making the further quantitative study impossible. Herein, a new ETIRS system has been designed and prepared by employing a cation-exchange membrane (Nafion) in the sampling hood. The using of the Nafion membrane can prevent the anions crossing over by confining the generated carbonates in the sampling hood without diffusing into the bulk electrolyte. Therefore, the collection efficiency of the carbonate products as well as the test accuracy of the carbonate current efficiency has been significantly improved. The result of CO stripping reaction shows that ca. 100% of the carbonate product is able to be collected in alkaline media by this new system. The influence of the experimental temperature to the carbonate current efficiency has been further studied on Pt/C toward EOR in alkaline media.
关键词： Transmission infrared spectroscopy,Ethanol oxidation reaction,Platinum,Alkaline media
更新于2025-09-23 15:23:52
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High-spectral-efficiency 600-Gbps/carrier Transmission Using PDM-256QAM Format
摘要： High-capacity carrier signals with high-order modulation are being considered for data center interconnection (DCI) applications as they can reduce the cost per bit by decreasing the number of devices and increasing fiber capacity. However, signal quality degradation due to device imperfections affecting the frequency response has limited the capacity per carrier of PDM-256QAM signals to under 400 Gbps. Here, it is possible to use a calibration method for dealing with device imperfections wherein a fixed equalizer separately calibrates the frequency response of the transmitter and receiver. Our previous study showed that PDM-256QAM signals at up to 48 GBaud could be transmitted over 100 km, while it used an experimental setup with total 3-dB analog bandwidth of 13 GHz and 20 GHz for transmitter and receiver, respectively. A micro-integrable tunable laser assembly (μITLA) with a typical linewidth of 20 kHz, maximum under 100 kHz. Actual data center interconnection (DCI) applications, however, are expected to use dense wavelength division multiplexing (WDM), so in this study, we examined transmission of 10-WDM 48-GBaud PDM-256QAM signals in a 50-GHz grid and evaluated the WDM penalties. The resulting spectral efficiency (SE) of 600-Gbps/carrier WDM transmissions was as high as 12.02 bit/s/Hz.
关键词： optical,digital coherent,fiber,optical transmission,signal processing,digital communication,high-order quadrature amplitude modulation
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE 38th International Conference on Electronics and Nanotechnology (ELNANO) - Kiev (2018.4.24-2018.4.26)] 2018 IEEE 38th International Conference on Electronics and Nanotechnology (ELNANO) - Investigation of the Structure and Optical Properties of Thin Copper Films
摘要： Copper nanolayers were formed using the vacuum magnetron-assisted sputtering in various technological modes (sedimentation speed, working pressure, discharge power). Results of microstructural study of the 1 nm to 65 nm thick copper nanofilms deposited on quartz, glass and silicon substrates are presented. Spectra of transmission and reflection coefficients of the copper nanofilms were studied in the wavelength range from 0.2 μm to 1.1 μm. The transmission and reflection spectra of films correspond well to the known spectra of bulk materials. The obtained results are of practical importance for development of nanostructural systems with the preset optical properties and for design of functional devices to be used in optoelectronics, information and energy-saving technologies.
关键词： transmission spectrum,microstructure,nanofilms,reflection spectrum
更新于2025-09-23 15:23:52
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[IEEE 2018 25th International Conference "Mixed Design of Integrated Circuits and System" (MIXDES) - Gdynia, Poland (2018.6.21-2018.6.23)] 2018 25th International Conference "Mixed Design of Integrated Circuits and System" (MIXDES) - Study of Wireless Communications Link at Subterahertz Frequencies Using FET-based Detectors
摘要： This paper focuses on the wireless link development deploying (sub)THz waves. The article describes authors’ initial approach to the research and experiments dealing with THz communications. Presented work summarises the theory and achieved results in a ?led of FET-based THz detectors and readout circuits aimed at wireless THz data transmission. Our main goal was to provide proper data transmission utilising (sub)THz carrier wave — this has been experimentally achieved at 170 GHz and 289 GHz.
关键词： THz,data transmission,FET-based detectors,wireless communications
更新于2025-09-23 15:23:52
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Localized Deformation and Fracture Behaviors in InP Single Crystals by Indentation
摘要： The indentation-induced deformation mechanisms in InP(100) single crystals were investigated by using nanoindentation and cross-sectional transmission electron microscopy (XTEM) techniques. The results indicated that there were multiple “pop-in” events randomly distributed in the loading curves, which were conceived to arise primarily from the dislocation nucleation and propagation activities. An energetic estimation on the number of nanoindentation-induced dislocations associated with pop-in effects is discussed. Furthermore, the fracture patterns were performed by Vickers indentation. The fracture toughness and the fracture energy of InP(100) single crystals were calculated to be around 1.2 MPa·m1/2 and 14.1 J/m2, respectively.
关键词： InP(100) single crystal,nanoindentation,fracture toughness,transmission electron microscopy,Pop-in
更新于2025-09-23 15:23:52
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Strain-Induced Metastable Phase Stabilization in Ga2O3 Thin Films
摘要： It is well known that metastable and transient structures in bulk can be stabilized in thin films via epitaxial strain (heteroepitaxy) and appropriate growth conditions that are often far from equilibrium. However, the mechanism of heteroepitaxy, particularly how the nominally unstable or metastable phase gets stabilized, remains largely unclear. This is especially intriguing for thin film Ga2O3, where multiple crystal phases may exist under varied growth conditions with spatial and dimensional constraints. Herein, the development and distribution of epitaxial strain at the Ga2O3/Al2O3 film-substrate interfaces is revealed down to the atomic resolution along different orientations, with an aberration-corrected scanning transmission electron microscope (STEM). Just a few layers of metastable α-Ga2O3 structure were found to accommodate the misfit strain in direct contact with the substrate. Following an epitaxial α-Ga2O3 structure of about couple unit cells, several layers (4~5) of transient phase appear as the intermediate structure to release the misfit strain. Subsequent to this transient crystal phase, the nominally unstable κ-Ga2O3 phase is stabilized as the major thin film phase form. We show that the epitaxial strain is gracefully accommodated by rearrangement of the oxygen polyhedra. When the structure is under large compressive strain, Ga3+ ions occupy only the oxygen octahedral sites to form a dense structure. With gradual release of the compressive strain, more and more Ga3+ ions occupy the oxygen tetrahedral sites, leading to volumetric expansion and the phase transformation. The structure of the transition phase is identified by high resolution electron microscopy (HREM) observation, complemented by the density functional theory (DFT) calculations. This study provides insights from the atomic scale and their implications for the design of functional thin film materials using epitaxial engineering.
关键词： κ-Ga2O3,misfit strain,α-Ga2O3,metastable phase,aberration-corrected scanning transmission electron microscopy
更新于2025-09-23 15:23:52
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Quality of extracellular vesicle images by transmission electron microscopy is operator and protocol dependent
摘要： Transmission electron microscopy (TEM) has nanometre resolution and can be used to distinguish single extracellular vesicles (EVs) from non-EV particles. TEM images of EVs are a result of operator image selection. To which extent operator image selection reflects the overall sample quality, and to which extent the images are comparable and reproducible, is unclear. In a first attempt to improve the comparability and reproducibility of TEM to visualise EVs, we compared operator image selection to images taken at predefined locations from the same grids, using four EV TEM preparation protocols, a single EV-containing sample and a single TEM instrument. Operator image selection leads to high-quality images that are more similar between the protocols. In contrast, images taken at predefined locations reveal differences between the protocols, for example in number of EVs per image and background quality. From the evaluated protocols, for only one protocol the operator image selection is comparable to the TEM images taken at predefined locations. Taken together, operator image selection can be used to demonstrate the presence of EVs in a sample, but seem less suitable to demonstrate the quality of a sample. Because images taken at predefined locations reflect the overall quality of the EV-containing sample rather than the presence of EVs alone, this is a first step to improve the comparability and reproducibility of TEM for monitoring the quality of EV-containing samples.
关键词： urine,negative staining,transmission electron microscopy (TEM),Exosomes,extracellular vesicles (EVs),microvesicles
更新于2025-09-23 15:23:52
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Vision-Based Measurement of Dust Concentration by Image Transmission
摘要： A vision-based measurement (VBM) of dust concentration with high accuracy can be used to analyze dust pollution and reveal the distribution law of dust concentration in a production workshop. In conventional VBM, grayscale and morphological features of a dust image are commonly used. However, their measurement accuracy is limited by the atmospheric light scattering effect of surrounding light and the occlusion effect of dust particles. Thus, a high accuracy VBM system is investigated that is based on the relationship between dust concentration and image transmission (RCT) model. Meanwhile, a calculation method for image transmission that utilizes the atmospheric light scattering effect and the occlusion effect of dust particles is proposed in this paper. The experimental results show that in the proposed system, the relative error is ±3.0%, the relative uncertainty is 2.05%, the correlation is 0.99, the measurement range is 0.5–1000 mg/m3, and the measurement period is 2 s. The RCT tends to be a negative correlation, which is a quadratic polynomial. The impact of the atmospheric light scattering effect and the occlusion effect of dust particles on measurement accuracy can be eliminated by utilizing image transmission. The proposed system can be used as an alternative measurement of dust concentration in the workshop.
关键词： machine vision,global atmospheric light,Dust concentration,transmission
更新于2025-09-23 15:23:52
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Circular Semi-Quantum Secret Sharing Using Single Particles
摘要： Semi-quantum secret sharing (SQSS) is an important branch of semi-quantum cryptography, and di?ers from quantum secret sharing (QSS) in that not all parties are required to possess quantum capabilities. All previous SQSS protocols have three common features: (i) they adopt product states or entangled states as initial quantum resource; (ii) the particles prepared by quantum party are transmitted in a tree-type way; and (iii) they require the classical parties to possess the measurement capability. In this paper, two circular SQSS protocols with single particles are suggested, where the ?rst one requires the classical parties to possess the measurement capability while the second one does not have this requirement. Compared with the previous SQSS protocols, the proposed SQSS protocols have some distinct features: (i) they adopt single particles rather than product states or entangled states as initial quantum resource; (ii) the particles prepared by quantum party are transmitted in a circular way; and (iii) the second protocol releases the classical parties from the measurement capability. The proposed SQSS protocols are robust against some famous attacks from an eavesdropper, such as the measure-resend attack, the intercept-resend attack and the entangle-measure attack, and are feasible with present quantum technologies in reality.
关键词： semi-quantum cryptography,semi-quantum secret sharing,measurement capability,circular transmission,single particles
更新于2025-09-23 15:23:52