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Mercury (Hg) is a global pollutant whose atmospheric deposition is a major input to the terrestrial and oceanic ecosystems. Gas‐particle partitioning (GPP) of gaseous oxidized mercury (GOM) redistributes speciated Hg between gas and particulate phase and can subsequently alter Hg deposition flux. Most 3‐dimensional chemical transport models either neglected the Hg GPP process or parameterized it with measurement data limited in time and space. In this study, CMAQ‐newHg‐Br (Ye et al., 2018, https://doi.org/10.1002/2017ms001161) was updated to CMAQ‐newHg‐Br v2 by implementing a new GPP scheme and the most up‐to‐date Hg redox chemistry and was run for the northeastern United States over January‐November 2010. CMAQ‐newHg‐Br v2 reproduced the measured spatiotemporal distributions of gaseous elemental mercury (GEM) and particulate bound mercury (PBM) concentrations and Hg wet deposition flux within reasonable ranges and simulated dry deposition flux in agreement with previous studies. The GPP scheme improved the simulation of PBM via increasing winter‐, spring‐ and fall‐time PBM concentrations by threefold. It also improved simulated Hg wet deposition flux with an increase of 2.1 ± 0.7 μgm2 in the 11‐month accumulated amount, offsetting half of the decreasing effect of the updated chemistry (−4.2 ± 1.8 μgm2). Further, the GPP scheme captured the observed Kp‐T relationship as reported in previous studies without using measurement data and showed advantages at night and in rural/remote areas where existing empirical parameterizations failed. Our study demonstrated CMAQ‐newHg‐Br v2 a promising assessment tool to quantify impacts of climate change and emission reduction policy on Hg cycling. Plain Language Summary: Mercury is a toxic global pollutant and can enter the food chain through atmospheric deposition to ecosystems. Atmospheric mercury was defined operationally in the forms of gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM) and particulate bound mercury (PBM). GEM is relatively inert, but GOM and PBM are highly soluble and readily removed from the air via deposition. GEM gets oxidized to GOM and GOM can be transformed to PBM through gas particle partitioning (GPP). CMAQ‐newHg‐Br v2 was updated from its predecessor via implementing the most up‐to‐date Hg redox chemistry and a new GPP scheme. The model improved the simulation of GEM, PBM, and Hg wet deposition. Most notably the model reproduced the observed partitioning coefficient and temperature relationship (Kp‐T) and improved nighttime and less polluted PBM simulations. CMAQ‐newHg‐Br v2 can be used to assess how climate change and emission reduction policy impact environmental Hg cycling. Key Points: CMAQ‐newHg‐Br was updated to version 2 with a new gas‐particle partitioning (GPP) scheme and the most up‐to‐date Hg redox chemistryCMAQ‐newHg‐Br v2 better simulated gaseous elemental mercury (GEM), particulate bound mercury (PBM) and Hg wet depositionThe new GPP scheme captured the observed Kp‐T relation not using measurement data and improved nighttime and less polluted simulations [ABSTRACT FROM AUTHOR]

This contribution discusses surrogate models that emulate the solution field(s) in the entire simulation domain. The surrogate uses the most characteristic modes of the solution field(s), in combination with neural networks to emulate the coefficients of each mode. This type of surrogate is well known to rapidly emulate flow simulations, but rather new for simulations of elastoplastic solids. The surrogate avoids the iterative process of constructing and solving the linearized governing equations of rate-independent elastoplasticity, as necessary for direct numerical simulations or (hyper-)reduced-order-models. Instead, the new plastic variables are computed only once per increment, resulting in substantial time savings. The surrogate uses a recurrent neural network to treat the path dependency of rate-independent elastoplasticity within the neural network itself. Because only a few of these surrogates have been developed for elastoplastic simulations, their potential and limitations are not yet well studied. The aim of this contribution is to shed more light on their numerical capabilities in the context of elastoplasticity. Although more widely applicable, the investigation focuses on a representative volume element, because these surrogates have the ability to both emulate the macroscale stress-deformation relation (which drives the multiscale simulation), as well as to recover all microstructural quantities within each representative volume element. [ABSTRACT FROM AUTHOR]

Individuals from the community who volunteer within prisons are an understudied population, despite previous research indicating the increase in involvement of the penal voluntary sector and benefits to both prisons and prisoners from effective implementation of volunteer programmes. This study aimed to identify the characteristics, motivations and experiences of individuals who volunteer in prisons. This was a systematic review conducted according to Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Peer-reviewed publications were identified through searchers of five electronic databases (MEDLINE, PsycINFO, Scopus, Applied Social Sciences Index & Abstracts and Social Sciences Database) without date restrictions, supplemented by hand searching and reference checking of retrieved articles. Explicit inclusion and exclusion criteria determined study eligibility. Study quality was appraised using standard tools. A narrative synthesis was conducted, and motivations were organised according to the Volunteer Function Inventory. Eight studies (five qualitative and three quantitative) reported a total of 764 volunteers across five countries. More than half of the included studies investigated individuals providing primarily religious volunteer support; volunteers in these studies were typically middle aged, White and female. Prison volunteers frequently described motivations related to altruistic or humanitarian values, as well as social reasons. Positive experiences of volunteering were related to personal benefits to volunteers. Negative experiences were related to a lack of support and challenges in volunteers' relationships with prison staff. Prison volunteer programmes have the ability to improve the psychological health of prisoners and provide a range of potential benefits to penal systems and volunteers themselves, but research on individuals who volunteer in prisons is limited. Difficulties in the volunteer role could be mitigated by developing formal induction and training packages, promoting closer integration with paid prison staff and providing ongoing supervision. Interventions to improve the volunteer experience should be developed and evaluated. • The first systematic review investigating the characteristics, motivations, and experiences of prison volunteers. • Generally, the volunteer profile was middle-aged, white, and female. • Volunteer motivations revolved around values or social reasons. • There were both positive and negative volunteer experiences. • More than half of the studies identified focused on individuals who provided primarily religious support to prisoners. • Developing knowledge on the prison volunteer can help to refine volunteer programmes and improve recruitment. [ABSTRACT FROM AUTHOR]

The rationality of urban transportation network layout directly affects the operational efficiency of urban transportation system. In this paper, a smart city public transport connection network optimization method based on particle swarm optimization algorithm is proposed. First, analyze the connection network mode and determine the network connection mode; Secondly, design the optimization objective and build the optimization objective function of the connection network; Set constraints; Then, considering the overall accessibility, set the connection point particles according to the particle swarm optimization algorithm, calculate the particle weight value, and solve the optimization objective function to realize the optimization of the public transport connection network. The results show that under the proposed method, the optimization error of the bus connection network is less than 0.30%, the coding accuracy of the connection point is more than 95%, and the time cost is less than 1.5s. It has better performance. [ABSTRACT FROM AUTHOR]

CHR12 and CHR23, which are members of the SWI2/SNF2 chromatin remodeling ATP family, play an important role in the growth and development of Arabidopsis thalianaL. They are involved in a series of physiological processes that encompass embryonic development to flowering. We used the microscope, electron microscope and gene chip to understand the role of CHR12 and CHR23 in the apical meristem development of Arabidopsis. We used yeast two-hybrid sieve library to screen the proteins that might interact with CHR23 and verified by yeast two-hybrid and bimolecular fluorescence complementary experiments. Finally, we analyzed the molecular mechanism of enhanced drought resistance of chr12 chr23 by RNA-seq and qPCR. The double mutants of chr12 chr23 have obvious developmental defects and these defects can be restored. Genes that were differentially expressed in chr12 chr23 stem tip tissues participated in more than 20 biological pathways. At the same time, we found that CHR23 could bind to the drought-stress-related protein Di19. In addition, chr12 chr23 double mutants were highly tolerant of drought stress. In this study, we prove that CHR12 and CHR23 are not only necessary for the maintenance and differentiation of stem cells in the SAM and RAM, but also participate in the regulationof hypocotyl growth. In addition, they also play an important role in drought stress response. [ABSTRACT FROM AUTHOR]

This article discusses the use of machine learning-based endoscopic classification for superficial mucosal lesions in hereditary diffuse gastric cancer (HDGC). The researchers aimed to validate the Cambridge criteria, which include six features, to aid in the detection and characterization of early signet ring cell carcinoma (SRCC) in pale areas. They recruited CDH1-PV carriers undergoing endoscopic surveillance and analyzed the performance of the criteria. They also developed a machine learning model based on the criteria and found that it achieved higher accuracy than the simple score. The researchers concluded that specific features of pale areas can be combined to accurately predict SRCC in HDGC, and a user-friendly diagnostic rule based on the machine learning model may improve performance. [Extracted from the article]

To investigate the effect of different process parameters on the powder feeding behaviour in coaxial laser cladding stainless steel powder with a fibre laser, high-speed cameras with different resolution, image analysis software and FLUENT software were employed to study the behaviour of conic powder jet stream under the nozzle. The feasibility of the method was also evaluated in detail. The obtained results show that grey level is not directly the powder distribution in the jet but rather a projection of this distribution. The powder distribution is an almost symmetrical Gaussian distribution in specific regions. As the powder feeding rate increases, the concentration of the convergence point increases; the carrier gas flow affects the gas and powder flow speed and concentration. The larger the carrier gas flow is, the greater the gas and powder flow speed are, but the concentration decreases, which is consistent with the grey image change law. The change of powder flow behaviour can be mainly attributed to the effect of gas flow rate on the movement tracks of powder particles. [ABSTRACT FROM AUTHOR]

In this study, we evaluated a new biopesticide containing different combinations of Photorhabdus luminescens (ATCC 29,999; Pl) and Bacillus thuringiensis subsp. aizawai (Bt) to leverage their insecticidal activity against Plutella xylostella. Mixtures containing proteins of various sizes were assayed to determine which combination of the two bacteria would yield the maximum insecticidal activity. A histopathologic slide revealed vacuole formations and rifts near the apical membrane (a symptom of Bt) and severe thinning of the intestinal wall (a symptom of Pl). When the two bacteria were cultured separately and then mixed, the insecticidal activity of the treatment reached 83.33% ± 8.82%. The insecticidal activity was elevated and significantly accelerated when Bt was mixed with both the Pl supernatant and the isolated protein with a molecular mass ≥ 100 kDa of Pl. These results highlight the potential of Pl as a potent bioinsecticide to economically and sustainably control Pl. xylostella and other lepidopteran pests. Key points: • Growth inhibition by Bacillus thuringiensis exerted a significant effect on insecticidal activity. • Large Photorhabdus luminescens proteins can accelerate the synergistic insecticidal effect on Plutella xylostella. [ABSTRACT FROM AUTHOR]

Summary: Background: Dupilumab is an antibody against interleukin‐4 receptor α, used in the treatment of atopic dermatitis (AD). Objectives: To evaluate the efficacy and safety of dupilumab in adult Chinese patients with moderate‐to‐severe AD. Methods: In this randomized, double‐blind, placebo‐controlled, parallel‐group, phase III study, conducted between December 2018 and February 2020, patients with AD received dupilumab (300 mg) or placebo once every 2 weeks for 16 weeks, and were followed up for 12 weeks. The primary efficacy endpoint was the proportion of patients with both an Investigator's Global Assessment score of 0–1 and a reduction from baseline of ≥ 2 points at week 16. Results: Overall, 165 patients (mean age 30·6 years; 71·5% male patients) were randomized; 82 patients were randomized to dupilumab and 83 patients were randomized to placebo. At week 16, 26·8% of patients in the dupilumab group and 4·8% of patients in the placebo group achieved the primary endpoint [difference 22·0%, 95% confidence interval (CI) 11·37–32·65; P < 0·001]. Compared with placebo, higher proportions of patients in the dupilumab group achieved ≥ 75% reduction in the Eczema Area and Severity Index score (57·3% vs. 14·5%; difference 42·9%, 95% CI 29·75–55·97; P < 0·001) and had ≥ 3‐point (52·4% vs. 9·6%; difference 42·8%, 95% CI 30·26–55·34; P < 0·001) and ≥ 4‐point (39·0% vs. 4·8%; difference 34·2%, 95% CI 22·69–45·72; P < 0·001) reductions in weekly average daily peak daily pruritus numerical rating scale scores. The incidence of treatment‐emergent adverse events during the treatment period was similar in the two groups. The incidence of conjunctivitis, allergic conjunctivitis and injection site reaction was higher in the dupilumab group than in the placebo group. Conclusions: In adult Chinese patients, dupilumab was effective in improving the signs and symptoms of AD and demonstrated a favourable safety profile. What is already known about this topic?Two randomized, placebo‐controlled phase III trials (SOLO 1 and SOLO 2) have demonstrated that dupilumab is effective and safe when used in the treatment of atopic dermatitis in adults.However, very few Chinese participants were included and, therefore, the efficacy and safety of dupilumab in this population is unclear. What does this study add?The findings of this randomized, placebo‐controlled phase III trial show that dupilumab is effective in improving the signs and symptoms of atopic dermatitis in adult Chinese patients and has a favourable safety profile in this population. Plain language summary available online [ABSTRACT FROM AUTHOR]

This paper studies the potential of using the successive over-relaxation iteration method with polynomial preconditioner (P(m)-SOR) to solve variably saturated flow problems described by the linearized Richards' equation. The finite difference method is employed to numerically discretize and produce a system of linear equations. Generally, the traditional Picard method needs to re-evaluate the iterative matrix in each iteration, so it is time-consuming. And under unfavorable conditions such as infiltration into extremely dry soil, the Picard method suffers from numerical non-convergence. For linear iterative methods, the traditional Gauss-Seidel iteration method (GS) has a slow convergence rate, and it is difficult to determine the optimum value of the relaxation factor w in the successive over-relaxation iteration method (SOR). Thus, the approximate optimum value of w is obtained based on the minimum spectral radius of the iterative matrix, and the P(m)-SOR method is extended to model underground water flow in unsaturated soils. The improved method is verified using three test examples. Compared with conventional Picard iteration, GS and SOR methods, numerical results demonstrate that the P(m)-SOR has faster convergence rate, less computation cost, and good error stability. Besides, the results reveal that the convergence rate of the P(m)-SOR method is positively correlated with the parameter m. This method can serve as a reference for numerical simulation of unsaturated flow. [ABSTRACT FROM AUTHOR]

Linked article: This Correspondence comments on Souter et al. Click here to view the article. [ABSTRACT FROM AUTHOR]

The intensification of farming and increased nitrogen fertiliser use, to satisfy the growing population demand, contributed to the extant climate change crisis. Use of synthetic fertilisers in agriculture is a significant source of anthropogenic Greenhouse Gas (GHG) emissions, especially potent nitrous oxide (N 2 O). To achieve the ambitious policy target for net zero by 2050 in the UK, it is crucial to understand the impacts of potential reductions in fertiliser use on multiple ecosystem services, including crop production, GHG emissions and soil organic carbon (SOC) storge. A novel integrated modelling approach using three established agroecosystem models (SPACSYS, CSM and RothC) was implemented to evaluate the associated impacts of fertiliser reduction (10%, 30% and 50%) under current and projected climate scenarios (RCP2.6, RCP4.5 and RCP8.5) in a study catchment in Southwest England. 48 unique combinations of soil types, climate conditions and fertiliser inputs were evaluated for five major arable crops plus improved grassland. With a 30% reduction in fertiliser inputs, the estimated yield loss under current climate ranged between 11% and 30% for arable crops compared with a 20–24% and 6–22% reduction in N 2 O and methane emissions, respectively. Biomass was reduced by 10–25% aboveground and by <12% for the root system. Relative to the baseline scenario, soil type dependent reductions in SOC sequestration rates are predicted under future climate with reductions in fertiliser inputs. Losses in SOC were more than doubled under the RCP4.5 scenario. The emissions from energy use, including embedded emissions from fertiliser manufacture, was a significant source (14–48%) for all arable crops and the associated GWP20. • SPACSYS, ROTHC and CSM models were integrated for modelling fertiliser reductions. • Scenario-based crop yields, GHG emissions, SOC rates, energy use were estimated. • Impacts on crops and grass in current and projected climate conditions were assessed. • Trade-offs between agricultural production and environmental impacts were shown. [ABSTRACT FROM AUTHOR]

Some traditional Chinese decoctions, such as Zhuyu Annao, exert favorable therapeutic effects on acute cerebral hemorrhage, hemorrhagic stroke, and other neurological diseases, but the underlying mechanism remains unclear. This study aimed to determine whether Zhuyu Annao decoction (ZYAND) protects the injured brain by promoting angiogenesis following intracerebral hemorrhage (ICH) and elucidate its specific mechanism. The effect of ZYAND on the nervous system of mice after ICH was explored through behavioral experiments, such as the Morris water maze and Rotarod tests, and its effects on oxidative stress were explored by detecting several oxidative stress markers, including malondialdehyde, nitric oxide, glutathione peroxidase, and superoxide dismutase. Real-time quantitative RT-PCR and WB were used to detect the effects of ZYAND on the levels of prolyl hydroxylase domain 3 (PHD3), hypoxia-inducible factor-1α (HIF-1α), and vascular endothelial growth factor (VEGF) in the brain tissues of mice. The effect of ZYAND on the NF-κB signaling pathway was detected using a luciferase reporter gene. A human umbilical cord vascular endothelial cell angiogenesis experiment was performed to determine whether ZYAND promotes angiogenesis. The Morris water maze test and other behavioral experiments verified that ZYAND improved the neurobehavior of mice after ICH. ZYAND activated the PHD3/HIF-1α signaling pathway, inhibiting the oxidative damage caused by ICH. In angiogenesis experiments, it was found that ZYAND promoted VEGF-induced angiogenesis by upregulating the expression of HIF-1α, and NF-κB signaling regulated the expression of HIF-1α by inhibiting PHD3. ZYAND exerts a reparative effect on brain tissue damaged after ICH through the NF-κB/ PHD3/HIF-1α/VEGF signaling axis. [ABSTRACT FROM AUTHOR]

We use the results of Moser and Knörrer on relations between geodesics on quadrics and solutions of the classical Neumann system to describe explicitly the geodesic scattering on hyperboloids. We explain the relation of Knörrer's reparametrisation with projectively equivalent metrics on quadrics introduced by Tabachnikov and independently by Matveev and Topalov, giving a new proof of their result. We show that the projectively equivalent metric is regular on the projective closure of hyperboloids and extend Knörrer's map to this closure. [ABSTRACT FROM AUTHOR]

Rainfall infiltration experiments were conducted on an unsaturated slope consisting of two-layer soils. The water content and the pore-water pressure in the slope were monitored. The monitored data are analysed and discussed in the paper. The analysis indicates that the water content and the pore-water pressure in the model slope change with the depth and that their change conditions are related with the physical properties of soils. These characteristics are different from single-layer slope significantly. The response time of the water content and the pore-water pressure increases with the slope depth. The water content and the pore-water pressure of the lower layer decrease faster than those of the upper layer. Under the same rainfall intensity, the water content and the pore-water pressure develop with the duration of rainfall until the steady seepage. The response time is quicker when the rainfall intensity is higher. However, the time effect is not significant near the slope surface. The pore-water pressure and water content in the upper layer of the model slope show more marked changes than those in the lower layer. Antecedent rainfall greatly affects the pore-water pressure and water content profiles before the steady seepage state, especially at early stage of rainfall infiltration in unsaturated regions. [ABSTRACT FROM AUTHOR]

In this work, we demonstrate for the first time the electroluminescence(EL) from a mesa isolated p-i-n diode based on silicon nanocrystals (Si NCs) embedded in a SiO2 matrix fabricated on a dielectric substrate. The structure fabricated on a dielectric substrate ensures that the EL signal originates entirely from the Si NC material. A small offset between the EL (1.28 eV) and photoluminescence(PL) (1.33 eV) peak energies has been observed at room temperature. We attribute this discrepancy to the different subset of light-emitting Si NCs in EL and PL. A model classifying Si NCs into connected NCs and isolated NCs is proposed. Atom probe tomography is employed to visualize the existence of isolated NCs and connected NCs. This model has been further studied using temperature dependent EL and PL, where a blue-shift of peak energy is observed as the temperature is increased. The blue-shift is attributed to the temperature dependent transport between the two subsets of NCs and the quenching of the PL emission from the connected NCs at higher temperatures. [ABSTRACT FROM AUTHOR]

This paper considers an adaptive neural event-triggered control problem of the molten steel level for twin roll strip casting systems with the inclined angle. Firstly, the model is improved and simplified into an affine nonlinear system by exploiting input compensation technique. Then, an adaptive observer is established based on radial basis function neural network (RBFNN). Furthermore, an adaptive event-triggered control scheme and corresponding adaptive updated laws are designed. It is proved that the proposed control method can guarantee the system output can follow reference signal and all closed-loop signals are bounded. Finally, the validity of the control scheme is verified through semi-experimental system dynamic model. [ABSTRACT FROM AUTHOR]

We extend the definition of relative Gromov–Witten invariants with negative contact orders to all genera. Then we show that relative Gromov–Witten theory forms a partial CohFT. Some cycle relations on the moduli space of stable maps are also proved. [ABSTRACT FROM AUTHOR]

Study Question: What is the true incidence of chromosomal mosaicism in embryos analyzed by preimplantation genetic testing (PGT).Summary Answer: The true incidence of chromosomal mosaicism is much lower than we usually surmise.What Is Known Already: In recent years, contemporary methods for chromosome analysis, along with the biopsy of more than one cell, have given rise to an increased rate of chromosomal mosaicism detection after preimplantation genetic testing for aneuploidy. However, the exorbitant incidence of mosaicism represents a dilemma and imposes restrictions on the application of PGT treatment. Concern has been raised about the possibility that the incidence of chromosomal mosaicism is overestimated and quite a few of the results are false-positive errors. However, studies verifying the diagnosis of chromosomal mosaicism and assessing the true incidence of chromosomal mosaicism are limited.Study Design, Size, Duration: A total of 1719 blastocysts from 380 patients who underwent PGT treatment were retrospectively analyzed to evaluate the typical incidence of mosaicism. Then 101 embryos donated by 70 couples were re-biopsied and dissected into three portions if available: trophectoderm (TE), inner cell mass (ICM), and the remaining portions. All the portions were tested using next-generation sequencing (NGS), and the results were compared to the original diagnosis.Participants/materials, Setting, Methods: The setting for this study was a university-affiliated center with an in-house PGT laboratory. All samples were amplified with multiple annealing and looping-based amplification cycles (MALBACs) and the NGS was carried out on a Life Technologies Ion Proton platform.Main Results and the Role Of Chance: A clinical TE biopsy revealed an incidence of 11.9% for diploid-aneuploid mosaicism (DAM), 17.3% for aneuploid mosaicism (AM) and 29.1% in total. After rebiopsy, 94.1% whole-chromosome aneuploidies and 82.8% segmental-chromosome aneuploidies were confirmed in the embryos. As for the mosaic errors, only 32 (31.7%) out of 101 embryos presented with uniform chromosomal aberrations in agreement with the original biopsy results, 15 (14.8%) embryos presented with de novo chromosomal aberrations, and 54 (53.5%) embryos showed a euploid profile in all portions. Among the 32 uniform embryos, the true mosaicism was confirmed in only 4 cases, where a reciprocal chromosomal aberration was identified; 14 embryos presented with identical mosaicism, providing the moderate evidence for true mosaicism; and 14 embryos displayed uniform full aneuploidies in all portions of embryo, revealing a high-grade mosaicism or a false-negative diagnosis. Logistical regression analysis revealed that the concordance rate with ICM was associated with the type and level of mosaicism. The concordance rate of segmental-chromosome mosaicism was significantly lower than whole-chromosome mosaicism (adjusted Odds Ratio (aOR): 5.137 (1.061, 24.876), P = 0.042) and compared to DAM, the concordance rate of AM was significantly higher (aOR: 6.546 (1.354, 31.655), P = 0.019). The concordance rate also increased with increasing levels of mosaicism (P < 0.001).Limitations, Reasons For Caution: This study was limited by a small sample size and the use of a single whole-genome amplification (WGA) method and NGS platform. These findings are only applicable to samples subjected to MALBAC amplification and Ion Proton platform, and studies involving larger sample sizes and multiple WGA methods and NGS platforms are required to prove our findings.Wider Implications Of the Findings: TE biopsy is reliable to detect whole-chromosome aneuploidies, but the ability to diagnose mosaicism is doubtful. More attention should be paid to false-positive and false-negative errors in NGS-based PGT, especially for laboratories using less stringent criteria for mosaicism classification (i.e. 20-80%), which might be subject to a much higher false-positive mosaicism rate in the practice.Study Funding/competing Interest(s): This study was supported by grants from the National Key R&D Program of China (No. 2016YFC1000206-5) and the National Natural Science Foundation of China (No. 81701509).Trial Registration Number: N/A. [ABSTRACT FROM AUTHOR]

To recycle vanadium from V-bearing steelmaking slag and V-bearing black shale, both were jointly roasted to generate vanadium-rich phase, and then vanadium was separated by magnetic separation in this study. The compositions of samples were determined by X-ray fluorescence meter and the phases in the samples were characterized using X-ray diffractometer. The experimental results showed that with increasing the ratio of CaO content to SiO2 content in the samples the vanadium separation efficiency first decreased, increased, and then decreased again. With increasing roasting temperature from 1423 to 1623 K, the vanadium separation efficiency increased. With increasing roasting time from one hour to four hours, the vanadium separation efficiency increased. The optimum conditions for vanadium recycling are the basicity of 1.2, roasting temperature of 1623 K, and roasting time of 4 hours. Under this condition, the separation efficiency of vanadium reaches 71.6%, and the concentrate contains 3.67% V2O5 and 46.9% Fe2O3. A flow for joint processing of V-bearing steelmaking slag and V-bearing black shale was proposed, which involves vanadium separating, and tailings utilizing. [ABSTRACT FROM AUTHOR]

Phenoxy-phosphazene (PPZ) oligomer (Rabitle® FP100) flame retardant (FR) was successfully incorporated into the colorless and transparent semi-alicyclic polyimide (CPI) film matrix derived from 1,2,4,5-cyclohexanetetracarboxylic dianhydride (CHDA) and 4,4'-oxydianiline (ODA) (PI-a, CHDA-ODA). The PPZ FR showed good miscibility with the PI-a matrix with a loading amount of up to 10 wt% in the composite films. PI-b (CHDA-ODA-FP100-5) film maintained good optical properties with the transmittance of 83.9% at the wavelength of 400 nm, the yellow index (b*) of 3.28, and the haze of 2.14%. PI-b film also showed good flame retardancy with the limiting oxygen indices (LOI) of 41.2% and the flammability rating of UL94 VTM-0. In addition, PI-b film exhibited the obviously reduced heat release rate (HRR) and total smoke production (THR) during the cone calorimeter measurement. At last, PI-b showed the glass transition temperature (Tg) and 5% weight loss temperature (T5%) of 325.0 and 404.3 °C, respectively, which was slightly lower than those of the pristine PI-a film (Tg = 346.8 °C; T5% = 431.6 °C). Continuous PI-b films with a length of 1000 m and a width of 1000 mm were successfully obtained on the demonstration production line by optimizing the processing parameters via the modified solvent cast technology. Similar thermal, optical, and flame retardancy properties and obviously improved tensile properties were observed for the mass production of PI-b film. [ABSTRACT FROM AUTHOR]

Landslide displacement evolution is important for predicting landslide geological disasters. Because landslide displacement monitoring data are limited, in this paper we propose a novel model for predicting landslide displacement, namely the kernel grey model with fractional operators (FKGM). By combining the advantages of fractional modeling, kernel function methods and grey models, we derived the theoretical framework of FKGM. The parameters of FKGM were obtained using particle swarm optimization algorithm. Then, FKGM was applied in a case study of a landslide in Hubei, China. The engineering geological characteristics of the landslide were analyzed, and seven factors including rainfall and the rate of the reservoir water-level change were selected as inputs. The results show that the mean absolute percentage error and mean square error of FKGM are smaller than those of the least square support vector machine (LSSVM) and the classical grey prediction model—GM(1,1). The influence of the FKGM parameters was investigated. Our results indicate that FKGM can be applied to reliably predict large deformation of landslides. [ABSTRACT FROM AUTHOR]

Learning point for cliniciansThis study identified a novel I GATA5 i variant (c.830C>T/p.P277L) in a fetus with Tetralogy of Fallot during prenatal diagnosis. Of which, CHD caused by single gene variant occupies 3-5%.[1] In this study, we identified a I GATA5 i variant (c.830C>T/p.P277L) in a TOF fetus using WES. [Extracted from the article]

Ti/TiBCN composite coatings were deposited on Ti6Al4V alloy using laser cladding technology. The comprehensive effects of laser specific energy on the microstructure, hardness, corrosion resistance and wear resistance of the Ti/TiBCN composite laser clad coatings were investigated. The phase characteristics of the coatings mainly comprise of Ti, Ti/TiBCN, TiC, Ti3Al, TiN and TiB2. The microstructure of coatings consists of coarse and fine dendritic crystals structure which is centrally symmetric structure with rod-like shape. The Ti/TiBCN composite coating cladding materials can be formed into homogeneous coatings at the laser specific energy of 330 J/mm². The metallurgical pores can be minimized but cannot be completely avoided by adjusting the scanning speed. The highest microhardness of the Ti/TiBCN composite laser clad coating was 1250 HV0.2, which was 3.6 times higher than the Ti6Al4V substrate. Meanwhile, the corrosion resistance and wear resistance of the Ti/TiBCN composite laser clad coating is much superior to that of the Ti6Al4V substrate, where the wear mechanism of coating was abrasive. [ABSTRACT FROM AUTHOR]

The pyrolysis of low-rank coal is considered as the optimal method of realizing clean and efficient production of blue coke, tar, and gas. The experiments of low-rank coal microwave pyrolysis under CO2, CH4, H2, and circulating gas (CG) are studied in a custom-designed microwave oven to clearly clarify the effects of reaction atmospheres on pyrolysis temperature, products yields, and spectroscopic characteristics of pyrolysis products by the analysis techniques of FT-IR and GC-MS. The results show that among four pyrolysis atmospheres, the temperature-rise rate and final pyrolysis temperature under H2 atmosphere are both highest, taking only 5.6 min to arrive at 750°C, and the final temperature is greater than 950°C. The liquid yields under CO2, CH4, H2, and CG atmospheres are 21.8, 24.4, 28.2, and 26.8 wt.%, respectively. The contents of –OH, aromatic ring C=C double bond, and –C=O in the solid product under CH4 atmosphere are highest, possibly because of the thermal polycondensation and the secondary degassing of the solid product. The hydrogenation of H free radicals dissociated from "rich hydrogen" gas results in an improvement in the alkane content and a decrease in the aromatic hydrocarbon content in tar, which is confirmed by the change in oxygen content in the solid product. The hydrogenation technique of circulating coal gas on low-rank coal microwave pyrolysis is economical, energy-efficient, and feasible, which is helpful in the development of coal processing technologies. [ABSTRACT FROM AUTHOR]

We investigated the working mechanisms of CdTe solar cells in which a second absorber-layer (defined as A2) with a lower bandgap was added through SCAPS simulation. The results show various positions and bandgap values of A2 are applicable at particular parameters, and the details are analyzed. We explored the essence of the improved cell performances via adding A2 for different occasions and provided some principles and models. Some new cognition for real cells was also presented. Additionally, we studied how the parameters of the wider-gap first absorber-layer influence the cell performances and its function as 439a back highly-resistant layer. [ABSTRACT FROM AUTHOR]

We report on the effect of exposure to atmospheric conditions on the THz conductivity of thin films of the topological insulator Bi2Se3. We find (1) two contributions of mobile charge carriers to the THz conductivity immediately after growth and (2) the spectral weight of the smaller of these decays significantly over a period of several days as the film is exposed to ambient conditions, while the other remains relatively constant. We associate the former with a bulk response and the latter with the surface. The surface response exhibits the expected robustness of the carriers from 2D topological surface states. We find no evidence for a third spectral feature derived from topologically trivial surface states. [ABSTRACT FROM AUTHOR]

We investigated the roles of neodymium trichloride (NdCl3) in regulating ascorbate-glutathione (AsA-GSH) cycle and chloroplast function of chromium (Cr)-stressed wheat seedlings. The findings showed that Cr stress markedly increased malondialdehyde (MDA) content, electrolytic leakage (EL), nonphotochemical quenching, and the activities of enzymes in AsA-GSH cycle, compared with control. However, Cr stress markedly reduced the ratios of reduced ascorbate to dehydroascorbate and reduced glutathione to oxidized glutathione, net photosynthetic rate, the contents of chlorophylls and carotenoids, maximum photochemical efficiency of PSII, photochemical quenching, and quantum efficiency of PSII photochemistry, as well as plant height, root length, and plant biomass. NdCl3 plus Cr stress markedly reduced MDA content and EL and improved other indicators, compared with Cr stress alone. Meanwhile, NdCl3 alone also markedly improved above indicators except MDA and EL, compared with control. Current results implied that NdCl3 improved AsA-GSH cycle and chloroplast function of wheat seedlings under Cr stress. [ABSTRACT FROM AUTHOR]

In this paper, we define genus‐zero relative Gromov–Witten invariants with negative contact orders. Using this, we construct relative quantum cohomology rings and Givental formalism. A version of Virasoro constraints also follows from it. [ABSTRACT FROM AUTHOR]

Currently, mathematical models such as the regression model, grey prediction model, and neural networks are commonly used to predict landslide displacement. In this study, we develop multi-data-driven models for prediction of landslide displacement. Multi-kernel learning and weighted learning methods are integrated with the grey prediction theory and three models are constructed to predict landslide displacement: the kernel-based grey model, multi-kernel grey model, and weighted multi-kernel grey model. All three models are simple to calculate and easy to program. The models were applied to a case study of the Baishuihe landslide in the Three Gorges reservoir, China. The influence of rainfall, reservoir water level, landslide rate, and historical displacement on the current displacement of the landslide were investigated, and multi-data-driven prediction models with input parameters (rainfall, reservoir water level, landslide rate, and historical displacement) and an output parameter (current displacement) were developed. The results show that the weighted multi-kernel grey model has better prediction accuracy than the kernel-based grey model and the multi-kernel grey model. These findings can be widely applied in practical landslide prediction. [ABSTRACT FROM AUTHOR]

An ancient, large-scale, river-damming landslide in Koushan Village, Wenchuan County, Sichuan Province, located in the upstream of the Minjiang River, had a large influence on the valley evolution of the Minjiang River. Our investigation estimated that the landslide volume was 1.5 billion m3. The elevation of the scarp is 2700 m, 1000 m above the present accumulation of the landslide. The residual dam is comparatively complete, with calcium cementation. The highest point of the dam is 221 m higher than the Minjiang River. The dammed lake extends for 38 km and reaches as far as Maoxian County. The investigation results indicate that an earthquake was probably the main cause of the landslide. The damming mechanism was associated with rock avalanches. These rock avalanches subsequently blocked the Minjiang River. The dam exhibits multi-stage breaching, which can be divided into overflow erosion and rapid cutting stages. The 14C dating results indicate that the landslide occurred at least 22,000 years ago and that the dam was breached at least 11,700 years ago. [ABSTRACT FROM AUTHOR]

Three viral contig sequences, which represented complete genome of a novel virus with three dsRNAs of 1,712 nucleotides (nt) (dsRNA1), 1,504 nt (dsRNA2) and 1,353 nt (dsRNA3), were found in tea-oil camellia plants by high-throughput sequencing analysis. The three dsRNAs were re-sequenced by RT-PCR cloning. The largest dsRNA, dsRNA1, had a single open reading frame (ORF) that encoded a putative 52.7-kDa protein of a putative viral RNA-dependent RNA polymerase (RdRp). DsRNA2 and dsRNA3 were predicted to encode putative capsid proteins (CPs) of 40.47 kDa and 40.59 kDa, respectively. The virus, which is provisionally named "tea-oil camellia deltapartitivirus 1", shared amino acid sequence itentities of 36.09-69.18% with members of the genus Deltapartitivirus on RdRp. Phylogenetic analysis based on RdRp also placed the new virus and other deltapartitiviruses together in a group, suggesting that this virus should be considered a new member of the genus Deltapartitivirus. [ABSTRACT FROM AUTHOR]

Background: Automated external defibrillators (AEDs) are critical in the chain of survival following out-of-hospital cardiac arrest (OHCA), yet few studies have reported on AED use and outcomes among pediatric OHCA. This study describes the association between bystander AED use, neighborhood characteristics and survival outcomes following public pediatric OHCA.Methods: Non-traumatic OHCAs among children less than18 years of age in a public setting between from January 1, 2013 through December 31, 2017 were identified in the CARES database. A neighborhood characteristic index was created from the addition of dichotomous values of 4 American Community Survey neighborhood characteristics at the Census tract level: median household income, percent high school graduates, percent unemployment, and percent African American. Multivariable logistic regression models assessed the association of OHCA characteristics, the neighborhood characteristic index and outcomes.Results: Of 971 pediatric OHCA, AEDs were used by bystanders in 10.3% of OHCAs. AEDs were used on 2.3% of children ≤1 year (infants), 8.3% of 2-5 year-olds, 12.4% of 6-11 year-olds, and 18.2% of 12-18 year-olds (p < 0.001). AED use was more common in neighborhoods with a median household income of >$50,000 per year (12.3%; p = 0.016), <10% unemployment (12.1%; p = 0.002), and >80% high school education (11.8%; p = 0.002). Greater survival to hospital discharge and neurologically favorable survival were among arrests with bystander AED use, varying by neighborhood characteristics.Conclusions: Bystander AED use is uncommon in pediatric OHCA, particularly in high-risk neighborhoods, but improves survival. Further study is needed to understand disparities in AED use and outcomes. [ABSTRACT FROM AUTHOR]

For many models of solids, we frequently assume that the material parameters do not vary in space nor that they vary from one product realization to another. If the length scale of the application approaches the length scale of the microstructure however, spatially fluctuating parameter fields (which vary from one realization of the field to another) can be incorporated to make the model capture the stochasticity of the underlying micro-structure. Randomly fluctuating parameter fields are often described as Gaussian fields. Gaussian fields, however, assume that the probability density function of a material parameter at a given location is a univariate Gaussian distribution. This entails for instance that negative parameter values can be realized, whereas most material parameters have physical bounds (e.g., Young's modulus cannot be negative). In this contribution, randomly fluctuating parameter fields are therefore described using the copula theorem and Gaussian fields, which allow different types of univariate marginal distributions to be incorporated but with the same correlation structure as Gaussian fields. It is convenient to keep the Gaussian correlation structure, as it allows us to draw samples from Gaussian fields and transform them into the new random fields. The benefit of this approach is that any type of univariate marginal distribution can be incorporated. If the selected univariate marginal distribution has bounds, unphysical material parameter values will never be realized. We then use Bayesian inference to identify the distribution parameters (which govern the random field). Bayesian inference regards the parameters that are to be identified as random variables and requires a user-defined prior distribution of the parameters to which the observations are inferred. For homogenized Young's modulus of a columnar polycrystalline material of interest in this study, the results show that with a relatively wide prior (i.e., a prior distribution without strong assumptions), a single specimen is sufficient to accurately recover the distribution parameter values. [ABSTRACT FROM AUTHOR]

A large contig with sequence similarities to members of the genus Robigovirus was identified by high-throughput sequencing analysis from a symptomless cherry accession. The complete genome sequence of this new virus is 8,384 nucleotides in length, excluding the 3' poly(A) tail. Its genome organization is very similar to those of four known robigoviruses, encoding a putative replicase, three 'triple gene block' proteins, a coat protein, and an unknown protein, 2a. Unlike the four cherry robigoviruses, the new virus does not contain a putative ORF5a. The full-length genome of the virus, which is provisionally named "cherry robigovirus 5" (CRV-5), is 52-57% identical to genome sequences of other robigoviruses. Phylogenetic analysis showed that CRV-5 and other robigoviruses group in a cluster, supporting its assignment to a new species in the genus Robigovirus. [ABSTRACT FROM AUTHOR]

All rocks undergo creep when under a long-term load, and shear sliding is a major failure mode of natural slopes. However, the mechanical properties of fractured mudstone differ from those of intact rock. To investigate these properties and the influence of normal stress and pre-cut crack length on mudstone shear creep characteristics, we performed shear creep tests on fractured mudstone. The experimental results show that axial load magnitude and crack length have a marked influence on the rock's shear creep behavior. The larger the axial compressive stress, the smaller the shear creep deformation. The longer the crack, the more significant the shear creep deformation. When stress is low, existing creep models can reflect the creep properties of mudstone well. However, most published creep models cannot accurately portray the nonlinear creep behavior of mudstone in a tertiary creep stage. We propose an improved time-dependent creep model that overcomes the shortcomings of the traditional models in describing nonlinear creep. The new model has fewer parameters and can be applied to practical engineering problems involving soft rock. During the shear creep tests on soft argillaceous samples under different loads, shear failure zones in fractured mudstone exhibited both gradual and sudden failure. The shear time-dependent model for mudstone developed in this study can effectively explain mudstone instability. [ABSTRACT FROM AUTHOR]

Many large-scale landslides have occurred along the Dadu River, in particular in the middle section of the river, located on the eastern edge of the Qinghai–Tibet Plateau. The large-scale Lantianwan landslide was triggered by the 1786 Moxi earthquake (Ms = 7.75) at Luding, Sichuan province, China. Field investigations and 3D discrete element methods were used to examine the landslide formation mechanism and simulate landslide movement. The evolution of the landslide can be divided into four stages: initiation, high-speed motion, debris flow, and accumulation and river blocking. The results indicate that tension cracking and horizontal sliding were the geological origins of the Lantianwan landslide. The Moxi earthquake combined with the magnifying effect of the topography and the back slope formed deep-dip tensile structural planes in the Lantianwan slope, which triggered the landslide. [ABSTRACT FROM AUTHOR]

We investigated the effects of astaxanthin supplementation and acute high intensity exercise on serum antioxidant capacity of human body, blood lactic acid and serum uric acid metabolism. Sixteen subjects were trained 28 days and were randomly divided into two groups: group A (experimental) and B (control). Four weeks later, all subjects underwent exercise on power bike. Immediately after exercise, the anti-oxidative capacity decreased in 2 groups, the lactic acid values of blood significantly increased, but compared with the group B the antioxidant capacity of the A group was significantly higher and blood lactate value lower. (1) Exercise can temporarily reduce the body's antioxidant capacity, increase blood lactic acid content, and slightly decrease blood uric acid content. (2) Astaxanthin intake can eliminate free radicals produced in the body, significantly reducing the increase in blood lactic acid and reducing blood uric acid value after acute high-intensity exercise. [ABSTRACT FROM AUTHOR]

Fracture mechanics parameters are crucial for evaluating the failure of a material; furthermore, the yielding zone near the crack tip is closely related to the ultimate bearing capacity. How to characterize these parameters has drawn a lot of attention from mechanics researchers. Currently, the digital image correlation (DIC) method, due to its advantage of being able to perform full-field, non-contact measurements, has great potential for application in the measurement of the mentioned parameters. In this paper, a bi-prism-based single lens (BSL) 3D DIC technique was utilized to determine the fracture mechanics parameters and the yielding zone size of the Ni-based superalloy GH4169 at room temperature and 650 °C. In the measurement, the displacement fields of single-edge cracked specimens under a uniaxial tensile load were measured using the BSL 3D DIC system. And then, the J integral and stress intensity factor K at room and high temperature were calculated from the displacement fields. Finally, the J integral calculated using the path integral method (J _ 1) and the J integral converted from the stress intensity factor K (J _ 2) were used to evaluate the yielding condition near the crack tip Yoneyama et al. (Strain 50(2):147–160, 2014), while a specific value was also determined as the critical small-scale yielding load from the variations of J _ 1 and J _ 2. Additionally, the relationship between the yielding zone size rp, calculated from K and the value ∆J = J _ 2 − J _ 1 was established, which was found to be linear. On the rp − ∆J curve, the intercept on the rp axis could be regarded as the critical size of small-scale yielding zone. [ABSTRACT FROM AUTHOR]

The friction coefficient, tip curvature, and different-width crack state influence the stress intensity factor (SIF). The maximum circumferential tensile stress (MTS) and minimum strain energy density criterion (S) face challenges in explaining the mode-II fracture propagation of cracks. The maximum radial shear stress (MSS) and modified twin shear stress factor (ITS) criteria are proposed as the brittle mode-II fracture criteria. The experiments and numerical analysis are also performed. The results indicate that the fracture angles of the MSS and ITS were similar and different from the results of MTS and S. The equivalent stress intensity factors (ESIFs) from the mixed mode I-II are proposed to determine the fracture mode. There are different fracture models for different cracks under tensile and compressive stresses. The ratio of the tensile strength to uniaxial compressive strength influenced the fracture angle of ITS. The lateral pressure coefficient (k) had a significant effect on the mode-II fracture angle when the angle between the crack and the vertical direction is less than 40° and the lateral pressure coefficient is more than 0. Because the same fracture mode k (k > 0) can inhibit mode-I fracturing, conversely, it can also promote mode-I fracturing. Experimental results and numerical simulations of fracture propagation under uniaxial compression confirmed that the theoretical results were correct. [ABSTRACT FROM AUTHOR]

The folding cooperativity is an important issue of protein folding dynamics. Since the native topology plays a significant role in determining the folding behavior of proteins, we believe that it also has close relationship with the folding cooperativity. In the present work, we perform simulations on proteins Naf-BBL, QNND-BBL, CI2, and SH3 with the Gō model and compare their different folding behaviors. By analyzing the weak cooperative folding of protein Naf-BBL in detail, we found that the folding of Naf-BBL shows relatively weak thermodynamic coupling between residues, and such weak coupling is found mainly between the nonlocal native contacts. This finding complements our understandings on the source of barrierless folding of Naf-BBL and promotes us to analyze the topological origins of the poor thermodynamic coupling of Naf-BBL. Then, we further extend our analysis to other two-state and multistate proteins. Based on the considerations of the thermodynamic coupling and kinetic coupling, we conclude that the fraction of scattered native contacts, the difference in loop entropy of contacts, and the long range relative contact order are the major topological factors that influence the folding cooperativity. The combination of these three tertiary structural features shows significant correlations with the folding types of proteins. Moreover, we also discuss the topological factors related to downhill folding. Finally, the generic role of tertiary structure in determining the folding cooperativity is summarized. [ABSTRACT FROM AUTHOR]

This paper explores possibility of refrigeration by using thermal-field emission of electrons in a coaxial cylindrical diode with a nanometer scale inner electrode (or cathode). Our calculation shows that it is possible to provide cooling at temperatures down to 200 K if the work function of the cathode is about 1 eV. The limitation on using a low work function cathode can be improved by applying an external axial magnetic field to create an additional potential barrier near the anode, more efficiently restricting the emission of low energy electrons (below the Fermi energy level). Because of this extra filtering process, emitters of arbitrary work functions can be used to provide an improved cooling capability from 300 to 10 K. The optimal conditions to maximize cooling power density are determined both numerically and analytically. The space charge effects of the emitted electrons in the gap are included self-consistently. [ABSTRACT FROM AUTHOR]

The Gō-like potential at a residual level has been successfully applied to the folding of proteins in many previous works. However, taking into consideration more detailed structural information in the atomic level, the definition of contacts used in these traditional Gō-models may not be suitable for all-atom simulations. Here, in this work, we develop a rational definition of contacts considering the screening effect in the crowded intramolecular environment. In such a scheme, a large amount of screened atom pairs are excluded and the number of contacts is decreased compared to the case of the traditional definition. These contacts defined by such a new definition are compatible with the all-atom representation of protein structures. To verify the rationality of the new definition of contacts, the folding of proteins CI2 and SH3 is simulated by all-atom molecular dynamics simulations. A high folding cooperativity and good correlation of the simulated [uppercase_phi_synonym]-values with those obtained experimentally, especially for CI2, are found. This suggests that the all-atom Gō-model is improved compared to the traditional Gō-model. Based on the comparison of the [uppercase_phi_synonym]-values, the roles of side chains in the folding are discussed, and it is concluded that the side-chain structures are more important for local contacts in determining the transition state structures. Moreover, the relations between side chain and backbone orderings are also discussed. [ABSTRACT FROM AUTHOR]

Lead-free KxNa1-xNbO3 (KNN) ceramics with x=0.10–0.80 were prepared by a conventional solid-state reaction method to investigate the influence of the K/Na ratio on their physical properties. It has been found that the KNN ceramics with x=0.45–0.60 exhibit quite different microstructures from those with other alkali compositional ratios. The lattice parameter discontinuity previously reported at x=0.475 has not been confirmed. The existence of a change in the line slopes of lattice parameter variation with x is verified in the vicinity of x=0.35. The permittivity [variant_greek_epsilon]′, piezoelectric constant d33, and planar electromechanical coupling coefficient kp show broad peaks in the compositional range of x=0.40–0.60, where d33 and kp are nearly independent of the K/Na ratio and all the ceramics have the high piezoelectric values of d33∼125 pC/N and kp∼0.41, respectively. From the analyses, we suggest that the high piezoelectric properties for the KNN ceramics near x=0.50 are closely related to their microstructures of well-faceted and uniformly distributed large grains rather than the widely believed morphotropic phase boundary effect of lattice parameter discontinuity. [ABSTRACT FROM AUTHOR]

Based on the experimental responsivity of single-period GaN/AlGaN midinfrared (MIR) heterojunction interfacial work-function internal photoemission (HEIWIP) detectors, we have optimized in detail the single- and multiperiod GaN/AlGaN MIR HEIWIPs to enhance the light absorption in the detectors. The yielded parameters of emitter, intrinsic, and bottom contact layers could achieve large improvement of the MIR peak absorption efficiency in the multiperiod GaN/AlGaN MIR HEIWIPs. Employing the concept of photon frequency upconversion, we have further investigated the realization of MIR pixel-less upconversion imaging through the integration of GaN/AlGaN MIR HEIWIP with a GaN/AlGaN violet light-emitting diode (LED). Under the optimized device structures, good imaging characteristics and high upconversion efficiency could be expected in the GaN/AlGaN HEIWIP-LED MIR upconverter. [ABSTRACT FROM AUTHOR]

The structural and optical properties of GaSbN single quantum wells grown on GaSb substrates by solid source molecular beam epitaxy have been investigated for N concentrations up to 1.5%. The presence of well-resolved and pronounced Pendellosung fringes, dynamical diffraction rods seen in the corresponding reciprocal space map, and triple-axis x-ray full width at half maximum of 10–11 arcsec of the substrate and epilayer peak indicates epilayers of excellent quality with smooth interfaces. Low-temperature photoluminescence (PL) exhibited sharp and discrete N-related PL line features below the GaSb band edge. Their dependence on N concentration as well as measurement temperature and excitation intensity of the PL strongly suggests that these lines correspond to highly localized N pair/cluster states. No significant effect of in situ annealing in Sb ambient on the PL features was observed, while ex situ annealing in N ambient led to the annihilation of these features. [ABSTRACT FROM AUTHOR]