Room temperature electroluminescence in the eye safe region of the spectrum over the range 1.7–2.1 μm is demonstrated from a thulium doped silicon diode. The same room temperature photoluminescence ...can be attained on a silicon-on-insulator substrate. The emission lines are from the first excited to ground state of the Tm3+ ion, 3F4→3H6. A detailed study has been made to establish the optimum implant and processing conditions for efficient room temperature luminescence. The importance of the correct placement of the thulium ions with respect to the depletion region edge and dislocation loops formed upon boron implantation has been established. Tm3+ has been demonstrated to lase in other systems and is the basis of widely applied, commercial, optically pumped 2 μm lasers. The demonstration of electroluminescence in silicon and luminescence on an SOI platform are necessary prerequisites for the potential development of Tm injection lasers and optical amplifiers.
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•Silicon light emitting diode at 2.1 μm achieved by ion implanting of thulium ions using standard silicon processing.•Room temperature (RT) electroluminescence is demonstrated under forward bias with a low one volt turn on voltage.•RT photoluminescence on an SOI platform is demonstrated, offering potential route towards an electrically pumped Tm laser.•Optimum process for dislocation loops to confine carriers to prevent surface recombination and enable RT luminescence.
Accurate sensing of trace amount of hydrogen without interference from environment is highly desirable in timely detection of possible leakage when using hydrogen as a clean energy source. Humidity ...in air is usually considered as the main challenge to the performance of room temperature hydrogen sensors. In this work, we have demonstrated distinctive sensing of H2 in humid environment at room temperature, using (002) oriented TiO2 thin film as active sensing material. Through first‐principle calculations in the framework of density functional theory, we have clarified the interaction between H2O and rutile TiO2 (002) surface. It was found that H2O can be easily split into –H and –OH with a negligible activation energy below 0.07 eV on the TiO2 (002) surface. Catalytic splitting of water has rather little effect on the height of Schottky barrier between Pt and the TiO2 (002) surface, thus resulting in ignorable impact on hydrogen sensing property. The (002) oriented TiO2 thin film hydrogen sensor could be utilized in various humid environment at room temperature.
Accurate sensing of trace amount of hydrogen without interference from environment is highly desirable in timely detection of possible leakage when using hydrogen as a clean energy source. The current results offer a solid basis for one to design separate alarm thresholds for water and hydrogen, so that humidity and hydrogen can be detected in a single device.
The Aktyuz Terrane in Kyrgyz North Tianshan is of particular interest due to the occurrence of high and ultrahigh pressure (HP–UHP) rocks and it containing the third largest gold deposit in Kyrgyz ...North Tianshan, i.e., Taldybulak Levoberezhny (abbreviated to Taldybulak Lev.). To constrain the ages of the host Kemin Complex and its auriferous monzogranite porphyry, detailed zircon U–Pb dating by laser ablation inductively coupled plasma-mass spectrometry (LA-ICPMS) and secondary ion mass spectroscopy (SIMS) and Lu–Hf isotopic analyses were carried out. The intensively altered auriferous monzogranite porphyry yielded two weighted mean ages of 444 ± 3 Ma (
n
= 14, mean squared weighted deviation (MSWD) = 0.49, by LA-ICPMS) and 440 ± 5 Ma (
n
= 8, MSWD = 0.82, by SIMS) that are indistinguishable within error ranges. Such ages are consistent with a previously reported sulfide Re–Os isochron age of 434 ± 18 Ma, supporting a Silurian porphyry gold mineralization. The granitic gneiss yielded a protolith age of 773 ± 7 Ma (
n
= 7, MSWD = 0.04) and two metamorphic ages of 514 ± 4 Ma (
n
= 8, MSWD = 0.09) and 483 ± 3 Ma (
n
= 11, MSWD = 0.04). Detrital zircons from one fuchsite schist sample yielded highly variable ages from 729 ± 13 Ma to 2,463 ± 30 Ma, with 12 data points weighted at 740 ± 5 Ma (MSWD = 0.95). The metamorphic overgrowth yielded a weighted mean age of 460 ± 4 Ma (
n
= 4, MSWD = 0.15). Detrital zircons in the migmatitic amphibolite are aged from 788 ± 7 Ma to 3,447 ± 32 Ma, with two major concentrations at 941 ± 7 Ma (
n
= 13, MSWD = 0.95) and 794 ± 5 Ma (
n
= 8, MSWD = 0.19). The metamorphic overgrowth yielded an average age of 555 ± 4 Ma (
n
= 8, MSWD = 0.65). The detrital and xenocryst zircons, and evolved εHf(t) values (−20.9 to −7.8) and old two-stage Hf model ages (1,367–3,159 Ma), revealed the presence of a Precambrian basement that may be dated back to the Archean Eon. The two metamorphic ages may correlate with oceanic subduction and continental collision, respectively.
PurposeThis study aims to examine the impact of digital transformation on firms’ value and explore the mediating impact of ESG performance and moderating impact of information ...interaction.Design/methodology/approachData was collected from companies listed on the Shanghai and Shenzhen stock exchange between 2012 and 2020 with 21,488 observational samples, featuring a selection of 3,348 companies. Panel data regression techniques were used to test the mediating role of ESG performance and the moderating role of information interaction.FindingsThe study found that digital transformation can improve firms’ ESG performance, which in turn positively affects their value. The firms that engage in more interaction with outsiders benefit more from digital transformation and have a higher value.Originality/valueThis study provides new theoretical insight into improving firms’ value through digital transformation and ESG performance. It is the first to discuss and study the moderating role of information interaction in the relationship between digital transformation and firms’ value.
Silicon photodetectors and camera chips are ubiquitous in the visible region of the spectrum and the near‐infrared. However, their large bandgap prevents their use at longer, technologically very ...important, wavelengths. The band‐edge‐modified rare‐earth detectors in silicon demonstrated here, fabricated using standard silicon technology tools, offer a route to these wavelengths and room‐temperature operation. Ion implantation of the usual n‐ and p‐type dopants, arsenic and boron, into commercial silicon wafers is used to fabricate a standard silicon p–n junction. Further implants of the rare earths, either Ce or Yb, are made into the depletion region to enable the extended long‐wavelength response. Detectivities up to 1.47 × 108 cm Hz1/2 W−1 and 2.89 × 107 cm Hz1/2 W−1 at 1.3 and 1.55 μm have been obtained with these simple planar devices. If integrated as lateral detectors in a silicon photonics platform, responsivities as good as standard silicon photodetectors in the visible and near‐infrared will be achievable.
A silicon photodetector with an extended wavelength performance well beyond the usual bandgap limit is described. This is achieved by doping with rare earths that exhibit the phenomenon of band‐edge modification of the rare earth levels. Importantly, the photodetector is fabricated using entirely silicon compatible process tools. The detector operates at room temperature in the important short‐wave infrared window.
Abstract Ubiquitin-proteasome system (UPS) is involved in vascular smooth muscle cell (VSMC) proliferation. Deubiquitinating enzymes (DUBs) have an essential role in the UPS-regulated stability of ...the substrate; however, the function of DUBs in intimal hyperplasia remains unclear. We screened DUBs to identify a protein responsible for regulating VSMC proliferation and identified USP14 protein that mediates cancer development, inflammation, and foam cell formation. USP14 promotes human aortic smooth muscle cell and A7r5 cell growth in vitro, and its inhibition or deficiency decreases the intimal area in the mice carotid artery ligation model. In addition, USP14 stabilizes Skp2 expression by decreasing its degradation, while Skp2 overexpression rescues USP14 loss-induced issues. The current findings suggested an essential role of USP14 in the pathology of vascular remodeling, deeming it a promising target for arterial restenosis therapy.
Bismuth molybdate thin films were deposited by reactive magnetron co-sputtering from two metallic targets in an argon/oxygen atmosphere, reportedly for the first time. Energy dispersive X-ray ...spectroscopy (EDX) analysis showed that the ratio of bismuth to molybdenum in the coatings can be effectively controlled by varying the power applied to each target. Deposited coatings were annealed in air at 673 K for 30 min. The crystalline structure was assessed by means of Raman spectroscopy and X-ray diffraction (XRD). Oxidation state information was obtained by X-ray photoelectron spectroscopy (XPS). Photodegradation of organic dyes methylene blue and rhodamine B was used for evaluation of the photocatalytic properties of the coatings under a visible light source. The photocatalytic properties of the deposited coatings were then compared to a sample of commercial titanium dioxide-based photocatalytic product. The repeatability of the dye degradation reactions and photocatalytic coating reusability are discussed. It was found that coatings with a Bi:Mo ratio of approximately 2:1 exhibited the highest photocatalytic activity of the coatings studied; its efficacy in dye photodegradation significantly outperformed a sample of commercial photocatalytic coating.
Ovarian carcinoma is one of the most aggressive gynecological malignant neoplasms and makes up 25-30% of all cancer cases of the female genital tract. Currently, resistance to traditional ...chemotherapy is a great challenge for patients with Epithelial ovarian cancer (EOC). Therefore, identifying novel agents for EOC treatment is essential and urgent.
MTS assay was used to analyze the cell viability and proliferation of cancer cells. Flow cytometry was employed to analyze cell cycle distribution and cell apoptosis. Protein signaling pathways were detected by western blot and immunohistochemical staining. Nude mouse experiment was performed to test the in vivo effect of platinum pyrithione (PtPT).
PtPT is a chemically well-characterized synthetic complex of platinum that potently inhibits proteasome-associated deubiquitinases USP14 and UCHL5 activity and shows selective cytotoxicity to multiple cancer cells without damaging DNA. We found that PtPT significantly accumulated ubquitinated-proteins and suppressed the proliferation of multiple EOC cells. Additionally, PtPT induced G2 phase arrest and apoptosis in both A2780 and SKOV3 cells. More importantly, animal experiments showed that PtPT dramatically suppressed the growth of EOC xenografts without obvious side effects.
These results suggest that through proteasome inhibition, PtPT significantly suppressed the proliferation of EOC in vitro and in vivo and could be developed as a novel agent for EOC treatment in the future.
A new gridded spatio-temporal big data fusion method is proposed for the organization and management of cropland big data, which could serve the analysis application of cropland quality evaluation ...and other analyses of geographic big data. Compared with traditional big data fusion methods, this method maps the spatio-temporal and attribute features of multi-source data to grid cells in order to achieve the structural unity and orderly organization of spatio-temporal big data with format differences, semantic ambiguities, and different coordinate projections. Firstly, this paper constructs a dissected cropland big data fusion model and completes the design of a conceptual model and logic model, constructs a cropland data organization model based on DGGS (discrete global grid system) and Hash coding, and realizes the unified management of vector data, raster data and text data by using multilevel grids. Secondly, this paper researches the evaluation methods of grid-scale adaptability, and generates distributed multilevel grid datasets to meet the needs of cropland area quality evaluation. Finally, typical data such as soil organic matter data, road network data, cropland area data, and statistic data in Da’an County, China, were selected to carry out the experiment. The experiment verifies that the method could not only realize the unified organization and efficient management of cultivated land big data with multimodal characteristics, but also support the evaluation of cropland quality.
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