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With the increasing demands of X‐ray detection and medical diagnosis, organic scintillators with intense and tunable X‐ray excited emission have been becoming important. To guarantee the X‐ray absorption, heavy atoms were widely added in reported organic scintillators, which led to emission quenching. In this work, we propose a new strategy to realize organic scintillators through the host‐guest doping strategy. Then the X‐ray absorption centers (host) and emission centers (guest) are separated. Under X‐ray excitation, these materials displayed intense and readily tunable emissions ranging from green (520 nm) to near infrared (NIR) regions (682 nm). Besides, the relationship between the X‐ray absorption and spatial arrangement of the heavy atoms in the host matrix was also revealed. The potential application of these wide‐range color tunable organic host‐guest scintillators in X‐ray imaging were demonstrated. This work provides a new feasible strategy for constructing high‐performance organic scintillators with tunable luminescence properties. [ABSTRACT FROM AUTHOR]

Siamese network based trackers formulate tracking as a similarity matching problem between a target template and a search region. Virtually all popular Siamese trackers use cross‐correlation to measure the similarity between the deep feature of template and search image. However, the emphasis for feature extraction in different parts of the image are the same. Besides, the global matching between the template and search region also seriously neglects the part‐level information and the deformation of targets during tracking. In this study, to tackle the above issues, a simple but effective Dynamic Adjust‐Head (SiamDAH) model is proposed to extract features from different parts of an object. In addition, an improved pixelwise cross‐correlation model (PWCC) is designed to enhance the naive cross‐correlation operation to produce multiple similarity maps associated with different parts of the target. Experiments on serval challenging benchmarks including OTB‐100, GOT‐10k, LaSOT, and TrackingNet demonstrate that the proposed SiamDAH outperforms many state‐of‐the‐art trackers and achieves leading performance. [ABSTRACT FROM AUTHOR]

Phosphorus (P) loss via runoff will reduce soil fertility and cause water eutrophication. Although P is lost as both particulate phosphorus (PP) and soluble phosphorus (SP), the existing P transport models for landscapes rarely consider PP and its exchange with surface runoff. We developed an integrated P transport model which coupled both SP and PP transport mechanisms based on the Rose–Gao model and assessed it via laboratory experiments. We also introduced a temporal varying P partition coefficient Kd into the model to reveal the impacts of rapid changes in the water environment on P adsorption and desorption. Experiments using kaolinite mixed soil and montmorillonite mixed soil were conducted under artificial rainfall events. The results show that the P transport model simulates the concentrations of eroded sediment, SP, and PP in surface runoff, with good agreement with the measured values (all R2 > 0.88). Kaolinite mixed soil had larger sediment and SP concentrations in the runoff than montmorillonite mixed soil. In addition, compared with the no Kd model (Gao model) and the constant Kd model, our model provided simulation results that most closely matched the experimental data. Considering the influence of eroded sediment and the P dynamic partitioning between sediment and water to the surface, the P transport model can provide an effective tool for P dynamics with water and sediment in surface runoff. [ABSTRACT FROM AUTHOR]

An efficient methodology for the synthesis of a variety of chromeno[3,4‐c]pyrrol‐4(2H)‐ones from 2‐hydroxychalcones and N‐substituted β‐enamine esters via I2/base promoted Michael addition/cyclization/lactonization/aromatization sequence have been developed, affording the coumarin heterocyclic derivatives in moderate to excellent yields. This approach is a highly efficient and convenient way to get derivatives of chromeno[3,4‐c]pyrrol‐4(2H)‐ones from readily accessible substrates under green reaction conditions. [ABSTRACT FROM AUTHOR]

A novel microwave roasting technology for formation of ZnO from zinc sulfide concentrate is presented. The dielectric properties and thermal behaviors of zinc sulfide concentrate and ZnS, CaO, MgO, ZnO, FeS, and ZnFe2O4, covering a temperature range of 25 to 1000°C at 2.45 GHz, are systematically investigated. The main microwave absorbing compounds are FeS and ZnS, while compounds like CaO, MgO, and SiO2 and other gangue exhibit poor absorbing properties. The sulfide concentrate temperature increase was divided into four stages, consistent with the dielectric properties. The morphology, phase and element contents of roasted were assessed covering the effect of roasting temperature, holding time, and particle size by SEM, XRD, and XRF. The optimal process conditions are roasting temperature 700°C, holding time 120 min, and the particle size less than 200 mesh. Microwave roasting mechanism shows microwave heat minerals (ZnS and FeS) selectively without heating gangue minerals (CaO, MgO, and SiO2), a significant temperature gradient develops between minerals. Thermal stress cause cracks effectively promote the dissociation of the monomers of useful minerals, increasing the interfacial area with O2, promoting the rate of desulfurization reaction. The work highlights harnessing microwave roasting as an effective and environmentally benign technology compared to conventional furnace technologies. [ABSTRACT FROM AUTHOR]

In flowing water the incipient motion of sediment can be affected by the presence of microbial biofilm growth. This article documents a series of flume experiments using non-uniform sediments, in which sediment entrainment was investigated for cases where the sediment was immersed in deionized water, so that no biofilm developed, and for cases where a bio-sediment was cultivated by placing the sediment in a mixture of natural water and nutrient solution. Differences in entrainment and the velocity at incipient motion were measured over an eight week period, as biofilm grew. It was found that the incipient motion phenomena were quite distinct between the two kinds of sediment. Sediment with biofilm was more stable and, over time, incipient velocity increased to a threshold level, before declining. Biofilm development is clearly an important control on the stability of sediments, especially in eutrophic water bodies. Two incipient velocity formulas were derived for sliding and rolling conditions. Film water theory was utilized to describe the cohesive force between sediment particles and the adhesive force generated by biofilm was introduced into the formula derivation; the time variation characteristics of biofilm strength and the features of the substrate were also taken into consideration. Such analyses can help to predict sediment transport changes due to biofilm presence in nutrient-rich water bodies. [ABSTRACT FROM AUTHOR]