This study aimed to investigate the effect of different coating processes on interlayer coating using ProCAST software and identify the preferred coating process so as to prepare an EH40/2205 composite plate with a coating interlayer of Ni-5 Fe-15 Co (wt.%) displaying good performance. The preparation and characterization tests were conducted to analyze the interlayer coating, the diffusion of elements at the bonding interface and the mechanical properties of the hot-rolled composite plate. The results showed that the coating rate increased linearly with an increase in the initial coating temperature, pressure difference and the width ratio of the suction layer. The interlayer coating was complete under the guidance of optimized process parameters, and the test results and simulations confirmed each other. The coated interlayer successfully blocked the diffusion of elements between the bonding surfaces. The tensile strength of the rolled composite plate was 580 MPa, which met the needs of the project. The tensile shear fracture occurred at EH40, which proved that the plate was well bonded.
In this study, high silica glass fiber fabric/liquid silicone rubber (HSGFF/LSR) composite sheet filled with hollow glass microspheres (HGM) was prepared. The effects of HGM content on the mechanical, thermal insulation and dynamic mechanical properties of the composite sheet were investigated. The results showed that the compatibility and interfacial properties between HGM and the matrix were improved after the HGM was treated with a silane coupling agent, KH550. Composite, in which the HGM content was 7 % by weight, shows the most advantageous mechanical, insulating and damping properties.
PL
Na bazie tkaniny z włókien kwarcowych (HSGFF) nasyconej ciekłym kauczukiem silikonowym (LSR) otrzymywano kompozyty napełniane mikrosferami szklanymi (HGM). Badano wpływ dodatku mikrosfer na właściwości mechaniczne, izolacyjność cieplną i właściwości dynamiczno-mechaniczne kompozytowych arkuszy. Stwierdzono, że modyfikacja mikrosfer szklanych za pomocą silanowego czynnika sprzęgającego KH550 poprawiła kompatybilność i oddziaływania międzyfazowe cząsteczek HGM i nasyconej ciekłym kauczukiem tkaniny z włókien szklanych. Najkorzystniejsze właściwości mechaniczne, izolacyjne i tłumiące wykazywał kompozyt, w którym zawartość HGM wynosiła 7 % mas.
Based on a fully phase encoding and phase retrieval algorithm, a diffractive-imaging-based optical encryption scheme with random illumination is proposed. In the encryption process, a QR code image is placed in the optic path to modulate the incident light and thus generate a random illumination, which has been demonstrated to enable the proposed scheme to resist the multi-slice ptychographic phase retrieval algorithm attack. The plaintext is phase-encoded, and then encrypted by two random phase masks. The diffraction pattern in the output plane is recorded as ciphertext by a CCD camera. For decryption, an iterative phase retrieval algorithm with median filtering operation is implemented. Simulation results demonstrate the effectiveness, security, and robustness of the proposal.
In order to simplify the optical setup and the encryption process, a diffractive-imaging-based optical encryption system using a single diffraction pattern is proposed. A predesigned binary mask is placed before the plaintext in the encryption process, and three randomly distributed phase only masks are placed in the optical path. Only one diffraction pattern needs to be recorded as ciphertext by CCD. In the decryption process, an iterative phase retrieval algorithm is applied, in which the predesigned binary mask acts as a support constraint in the input plane. After the iterative process, an interpolation operation for the zero-valued pixels is also implemented. The effectiveness and robustness of the proposal are demonstrated by numerical simulation results.
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The essential oil extracted from Nardostachys chinensis Batal (NCB) was analyzed by gas chromatography-mass spectrometry (GC-MS) combined with two chemometric resolution methods (CRM), heuristic evolving latent projections (HELP), and selective ion analysis (SIA). Qualitative analysis was performed by comparing the obtained pure mass spectra with those in National Institute of Standards and Technology (NIST) mass spectra database. Identification of some compounds was assisted by comparison of programmed temperature retention indices (PTRIs). The quantitative results were obtained by overall volume integration (OVI). A total of 69 compounds in the essential oil of N. chinensis Batal were identified, accounting for 93.98% of the total content. The major compounds were (−)-spathulenol, epiglobulol, trans-longipinocarveol, and patchouli alcohol which contribute to the antimicrobial and antioxidant activity. The results showed that the efficiency and reliability were greatly improved by use of chemometric techniques and programmed temperature retention index as assistants of GC-MS in identification of the plant essential oil.
This paper summarises work undertaken during the Catacombs of Anubis project which has examined the Dog Catacomb at North Saqqara. It examines the condition and natural decay of the monument as well as looking at the environs of the Lake of Abusir at the northern end of the site.
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Land use/cover change (LUCC) is one of the main factors that influence the terrestrial carbon (C) and nitrogen (N) cycle. We examined the effects of land use/cover change on topsoil C, N, and microbial biomass C, N (MBC, MBN) and their relationship with other soil properties in the middle of Heihe river basin along a land use change gradient of 100-year farmland, 27-year farmland, 33-year pine forest, 28-year poplar forest, and 21-year shrubland, as well as native desert from which all the above cultivated systems are converted. Results revealed that land use conversion from native desert to the above cultivated ecosystems not only changed the basic eco-hydrological factors of the soil, such as improving the soil moisture and field capacity, decreasing the pH and salinity, but also altered the nutrient factors, such as improving the concentrations of soil organic C (SOC), total N (TN), MBC, MBN, NO3--N and NH4+-N,. With the increase of cultivated years, land use conversion had an increasing impact on the C and N sequestration and soil nutrients stabilization.
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W artykule omówiono możliwe przyczyny niezbalansowania napięcia punktu neutralnego w przekształtniku z diodami poziomującymi oraz wpływ na to napięcie nakładania się fal nośnych w modulacji. W przedstawionym schemacie modulacji nakładanie się fal jest wynikiem zwiększenia amplitudy jednej z tych fal. Przedstawiono dyskusję wpływu proponowanej techniki na zmiany napięcia punktu neutralnego oraz zależności między współczynnikiem modulacji, stopniem nakładania się fal i współczynnikiem mocy. Wyniki badań symulacyjnych potwierdzają skuteczność działania.
EN
To address the neutral point voltage balance problem of the diode clamped three-level inverter, this paper analyzes the causes of unbalanced neutral point voltage and studies the impact of the carriers overlap on the neutral point voltage. A simple neutral point voltage control scheme using carrier overlapping sinusoidal pulse width modulation (SPWM) is proposed. The proposed scheme does not change the modulation waves, the amplitude of one carrier is increased to overlap the other carrier, and the neutral point voltage can be maintained balance by increasing the carriers amplitudes. The influence of the vertical overlap of carriers on neutral point balance is investigated in depth. The relationship among the neutral point voltage variation, modulation index, overlap of the carriers, and power factor is discussed in this paper. Simulation results show the neutral point voltage balancing control strategy based on SPWM is effective.
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To study the differences between long-pulse and short-pulse laser-induced damage in optical dielectric thin films, temperature distributions in single-layer HfO2 films, multi-layer HfO2/SiO2 films, and HfO2 films with high-absorptive inclusions induced by 1 ms and 10 ns lasers are analyzed based on the temperature field theory. Through our calculations, the damage property differences between millisecond and nanosecond lasers are summarized. The results for single-layer films show that 1 ms laser is easier to damage the substrate than 10 ns laser. For multi-layer films, the laser field effect is weaker when irradiating by 1 ms laser. Furthermore, when inclusions are introduced, the film is easier to be damaged by 10 ns laser, which means that 10 ns laser is more sensitive to the inclusions.
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