Simulation-aided infrared thermography with decomposition-based noise reduction for detecting defects in ancient polyptychs.

In recent years, the conservation and protection of ancient cultural heritage have received increasing attention, and non-destructive testing (NDT), which can minimize the damage done to the test subject, plays an integral role therein. For instance, NDT through active infrared thermal imaging can be applied to ancient polyptychs, which can realize accurate detection of damage and defects existing on the surface and interior of the polyptychs. In this study, infrared thermography is used for non-invasive investigation and evaluation of two polyptych samples with different pigments and artificial defects, but both reproduced based on a painting by Pietro Lorenzetti (1280/85-1348) using the typical tempera technique of the century. It is noted that, to avoid as far as possible secondary damages done to the ancient cultural heritages, repeated damage-detection experiments are rarely carried out on the test subjects. To that end, numerical simulation is used to reveal the heat transfer properties and temperature distributions, as to perform procedural verification and reduce the number of experiments that need to be conducted on actual samples. Technique-wise, to improve the observability of the experimental results, a total variation regularized low-rank tensor decomposition algorithm is implemented to reduce the background noise and improve the contrast of the images. Furthermore, the efficacy of image processing is quantified through the structural-similarity evaluation.

Overload performance study and fabrication of the capacitive pressure-sensitive chip with linkage film.

In order to satisfy the demands of pressure measurement under high overload conditions, the overload characteristics of the capacitive pressure-sensitive chip with linkage film are studied. Through the simulation and analysis for the stress distribution of this sensitive structure and in light of the dimension effect of the tensile strength of monocrystalline silicon, the influence of sizes of the sensitive structure on the overload pressure is expounded. The simulated results illustrate that the maximum overload pressure can exceed 200 times the full-scale (FS) when appropriately adjusting the sizes of the sensitive structure. The proposed chip is fabricated using SOI wafers combined with bonding technology. Our experimental results show that the sample chip has a linear response in the pressure range of 25-100 kPa, and its overload pressure is 4.5 MPa, reaching 45 times the full-scale.

Synergic removal of tetracycline using hydrophilic three-dimensional nitrogen-doped porous carbon embedded with copper oxide nanoparticles by coupling adsorption and photocatalytic oxidation processes.

Adsorption and photocatalytic oxidation are promising technologies for eliminating antibiotics (e.g. tetracycline) in aquatic environments. However, traditional powdery nanomaterials are limited by drawbacks of difficult separation and lack of synergistic function, which do not conform to the practical demand. Herein, we developed a simple one-step gelation-pyrolysis route to fabricate hydrophilic three-dimensional (3D) porous photocatalytic adsorbent, in which CuO nanoparticles are uniformly and firmly embedded in nitrogen-doped (N-doped) porous carbon frameworks. The obtained N-doped carbon/CuO bulky composites exhibited excellent ability to adsorb tetracycline hydrochloride (TC), which was subsequently photo-oxidized under visible light. Their hydrophilic nature favors the adsorption processes toward TC, with a maximum adsorption capacity reaching 25.03 mg∙g-1. In addition, >94.4% of TC molecules could be photo-degraded in 4 h with good cycling efficiency after three consecutive tests. Finally, a reaction scheme for removal process of TC was proposed. The obtained 3D porous N-doped carbon/CuO nanocomposites show great promise for efficient removal of antibiotics in aqueous solution by synergistically utilizing adsorption and photocatalytic oxidation processes.

[New quantificational indexes in modern study of soil organic matter].

In modern study of soil organic matter, many new quantificational indexes and relevant testing methods, e.g., DOC, WSOC, HWC, ROC, MBC, MBN, PMC, PMN, Glu, Gla, Man, Mur, delta 13C, and CPMI, came forth with deepening study. Because they are disorderly and unsystematic, it is necessary to clarify these indexes. This paper summarized their origin, concept, and testing method, which is of significance in the modern study of soil organic matter.