•Based on linear energy transfer and storage, two coefficient in the presence of IR was proposed.•The characterizing of total strain energy and elastic strain energy of rock under uniaxial loading by ...IR was solved.•Precursor methods for rock failure in the presence of infrared radiation under uniaxial loading.
Water saturated rock strain energy evolution was measured using infrared radiation (IR) under uniaxial load of sandstone samples. The variation in the characteristics of total strain, elastic strain, dissipated strain energies and maximum IR of saturated rock under stress were analyzed. The results reveal the degree of saturation has a significant effect on rock strain energy. The total strain and elastic strain energies correlated linearly negatively, dissipative strain energy were correlated exponentially negatively, and maximum infrared radiation variance (IRV) correlated quadratically at peak stress point with different degree of saturation of rock samples. The relationship between total strain, elastic strain energies, and ΔIRV was a linear function under different saturated conditions. It was found that there was a linear energy transfer and linear energy storage function in the rock. Based on linear energy transfer and storage, two coefficient in the presence of IR were introduced, i.e., the Total Energy Infrared Radiation Coefficient (TEIRC) and Energy Storage Infrared Radiation Coefficient (ESIRC). These can be used with variation in infrared radiation variance (ΔIRV) to determine total strain and elastic strain energies of saturated rock. Furthermore, a quantitative analysis index of energy dissipation infrared radiation ratio (EDIRR), i.e. the ratio of dissipative strain energy to ΔIRV, has been proposed which can be used to predict and identify the failures of saturated rock. The inflection point of rock EDIRR from horizontal to rapid growth can be regarded as the precursor point for rock failure, and the EDIRR mutation after the precursor point can be used as the new criterion to monitor rock failure and instability.
Photodynamic therapy (PDT) is an important cancer treatment modality due to its minimally invasive nature. However, the efficiency of existing PDT drug molecules in the deep‐tissue‐penetrable ...near‐infrared (NIR) region has been the major hurdle that has hindered further development and clinical usage of PDT. Thus, herein a strategy is presented to utilize a resonance energy transfer (RET) mechanism to construct a novel dyad photosensitizer which is able to dramatically boost NIR photon utility and enhance singlet oxygen generation. In this work, the energy donor moiety (distyryl‐BODIPY) is connected to a photosensitizer (i.e., diiodo‐distyryl‐BODIPY) to form a dyad molecule (RET‐BDP). The resulting RET‐BDP shows significantly enhanced absorption and singlet oxygen efficiency relative to that of the acceptor moiety of the photosensitizer alone in the NIR range. After being encapsulated with biodegradable copolymer pluronic F‐127‐folic acid (F‐127‐FA), RET‐BDP molecules can form uniform and small organic nanoparticles that are water soluble and tumor targetable. Used in conjunction with an exceptionally low‐power NIR LED light irradiation (10 mW cm−2), these nanoparticles show superior tumor‐targeted therapeutic PDT effects against cancer cells both in vitro and in vivo relative to unmodified photosensitizers. This study offers a new method to expand the options for designing NIR‐absorbing photosensitizers for future clinical cancer treatments.
Resonance energy transfer constructed NIR‐absorbing BODIPY‐based photosensitized dyad nanoparticles are developed. These nanoparticles enable targeted photodynamic therapy upon application of low‐power NIR LED light irradiation. This work provides a new concept for the design of biocompatible nanoparticles with significantly improved NIR sensitivity, which is key to photodynamic therapy development.
In this research paper, a new method is developed that can be used as a precursor of violent rock failure. It is based on measuring the characteristics of rock failure using infrared radiation (IR) ...under uniaxial cyclic loading and unloading. The loading–unloading response ratio (LURR) is determined based on IR indexes such as average infrared radiation temperature (AIRT) and infrared radiation temperature rate (IRTR). The results show that the LURR based on AIRT revealed an overall rising trend and mutation that occurred in the last cycle, which can be used as a precursor of the imminent rock failure. By contrast, the LURR based on IRTR has a noticeable ‘mutation‐rapid decrease’ in the middle and later periods of cyclic loading and unloading, which can also be considered as an early precursor of rock failure. Combined with the precursors of the imminent rock failure, the categorized warning of rock failure is recognized.
Abstract
In view of increasing drug resistance, ecofriendly photoelectrical materials are promising alternatives to antibiotics. Here we design an interfacial Schottky junction of Bi
2
S
3
/Ti
3
C
2
...T
x
resulting from the contact potential difference between Ti
3
C
2
T
x
and Bi
2
S
3
. The different work functions induce the formation of a local electrophilic/nucleophilic region. The self-driven charge transfer across the interface increases the local electron density on Ti
3
C
2
T
x
. The formed Schottky barrier inhibits the backflow of electrons and boosts the charge transfer and separation. The photocatalytic activity of Bi
2
S
3
/Ti
3
C
2
T
x
intensively improved the amount of reactive oxygen species under 808 nm near-infrared radiation. They kill 99.86% of
Staphylococcus aureus
and 99.92% of
Escherichia coli
with the assistance of hyperthermia within 10 min. We propose the theory of interfacial engineering based on work function and accordingly design the ecofriendly photoresponsive Schottky junction using two kinds of components with different work functions to effectively eradicate bacterial infection.
To elucidate the intrinsic broadband infrared (IR) emission properties of active galactic nuclei (AGNs), we analyze the spectral energy distributions (SEDs) of 87 z 0.5 Palomar-Green (PG) quasars. ...While the Elvis AGN template with a moderate far-IR correction can reasonably match the SEDs of the AGN components in ∼60% of the sample (and is superior to alternatives such as that by Assef), it fails on two quasar populations: (1) hot-dust-deficient (HDD) quasars that show very weak emission thoroughly from the near-IR to the far-IR, and (2) warm-dust-deficient (WDD) quasars that have similar hot dust emission as normal quasars but are relatively faint in the mid- and far-IR. After building composite AGN templates for these dust-deficient quasars, we successfully fit the 0.3-500 m SEDs of the PG sample with the appropriate AGN template, an infrared template of a star-forming galaxy, and a host galaxy stellar template. 20 HDD and 12 WDD quasars are identified from the SED decomposition, including seven ambiguous cases. Compared with normal quasars, the HDD quasars have AGNs with relatively low Eddington ratios and the fraction of WDD quasars increases with AGN luminosity. Moreover, both the HDD and WDD quasar populations show relatively stronger mid-IR silicate emission. Virtually identical SED properties are also found in some quasars from z = 0.5 to 6. We propose a conceptual model to demonstrate that the observed dust deficiency of quasars can result from a change of structures of the circumnuclear tori that can occur at any cosmic epoch.
The exploitation of the stable and earth-abundant electrocatalyst with high catalytic activity remains a significant challenge for hydrogen evolution reaction. Being different from complex ...nanostructuring, this work focuses on a simple and feasible way to improve hydrogen evolution reaction performance via manipulation of intrinsic physical properties of the material. Herein, we present an interesting semiconductor-metal transition in ultrathin troilite FeS nanosheets triggered by near infrared radiation at near room temperature for the first time. The photogenerated metal-phase FeS nanosheets demonstrate intrinsically high catalytic activity and fast carrier transfer for hydrogen evolution reaction, leading to an overpotential of 142 mV at 10 mA cm
and a lower Tafel slope of 36.9 mV per decade. Our findings provide new inspirations for the steering of electron transfer and designing new-type catalysts.
Extension of the polycyclic benzo-rhenapyrylium structure by a fused metallaaromatic ring and a benzene unit are reported. The dirhena-aromatic complex 4 shows strong absorption in the visible region ...and a significant absorption in the near-infrared (NIR) region (
λ
max
= 842 nm). DFT calculations are performed to understand its aromatic nature and electronic behavior.
Extension of the polycyclic benzo-rhenapyrylium structure by a fused metallaaromatic ring and a benzene unit are achieved.
ABSTRACT We present a large, uniform analysis of young (≈10–150 Myr) ultracool dwarfs, based on new high-precision infrared (IR) parallaxes for 68 objects. We find that low-gravity ( vl-g ) late-M ...and L dwarfs form a continuous sequence in IR color–magnitude diagrams, separate from the field population and from current theoretical models. These vl-g objects also appear distinct from young substellar (brown dwarf and exoplanet) companions, suggesting that the two populations may have a different range of physical properties. In contrast, at the L/T transition, young, old, and spectrally peculiar objects all span a relatively narrow range in near-IR absolute magnitudes. At a given spectral type, the IR absolute magnitudes of young objects can be offset from ordinary field dwarfs, with the largest offsets occurring in the Y and J bands for late-M dwarfs (brighter than the field) and mid-/late-L dwarfs (fainter than the field). Overall, low-gravity ( vl-g ) objects have the most uniform photometric behavior, while intermediate gravity ( int-g ) objects are more diverse, suggesting a third governing parameter beyond spectral type and gravity class. We examine the moving group membership for all young ultracool dwarfs with parallaxes, changing the status of 23 objects (including 8 previously identified planetary-mass candidates) and fortifying the status of another 28 objects. We use our resulting age-calibrated sample to establish empirical young isochrones and show a declining frequency of vl-g objects relative to int-g objects with increasing age. Notable individual objects in our sample include high-velocity (≳100 km s −1 ) int-g objects, very red late-L dwarfs with high surface gravities, candidate disk-bearing members of the MBM20 cloud and β Pic moving group, and very young distant interlopers. Finally, we provide a comprehensive summary of the absolute magnitudes and spectral classifications of young ultracool dwarfs, using a combined sample of 102 objects found in the field and as substellar companions to young stars.
We have produced the next generation of quasar spectral energy distributions (SEDs), essentially updating the work of Elvis et al. by using high-quality data obtained with several space- and ...ground-based telescopes, including NASA's Great Observatories. We present an atlas of SEDs of 85 optically bright, non-blazar quasars over the electromagnetic spectrum from radio to X-rays. The heterogeneous sample includes 27 radio-quiet and 58 radio-loud quasars. Most objects have quasi-simultaneous ultraviolet-optical spectroscopic data, supplemented with some far-ultraviolet spectra, and more than half also have Spitzer mid-infrared Infrared Spectrograph spectra. The X-ray spectral parameters are collected from the literature where available. The radio, far-infrared, and near-infrared photometric data are also obtained from either the literature or new observations. We construct composite SEDs for radio-loud and radio-quiet objects and compare these to those of Elvis et al., finding that ours have similar overall shapes, but our improved spectral resolution reveals more detailed features, especially in the mid- and near-infrared.
This article aims to overview infrared (IR) spectroscopy. Simultaneously, it outlines mid-infrared (MIR), near-infrared (NIR), and far-infrared (FIR) or terahertz (THz) spectroscopy separately, and ...compares them in terms of principles, characteristics, advantages, and applications. MIR spectroscopy is the central spectroscopic technique in the IR region, and is mainly concerned with the fundamentals of molecular vibrations. NIR spectroscopy incorporates both electronic and vibrational spectroscopy; however, in this review, I have chiefly discussed vibrational NIR spectroscopy, where bands due to overtones and combination modes appear. FIR or THz spectroscopy contains both vibrational and rotational spectroscopy. However, only vibrational FIR or THz spectroscopy has been discussed in this review. These three spectroscopy cover wide areas in their applications, making it rather difficult to describe these various topics simultaneously. Hence, I have selected three key topics: hydrogen bond studies, applications of quantum chemical calculations, and imaging. The perspective of the three spectroscopy has been discussed in the last section.
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