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The hierarchical MoS 2 @PEDOT/rGO hybrid exhibited outstanding electromagnetic wave absorption performance stemming from the synergistic effect of well-matched impedance and enhanced dielectric loss. [Display omitted] • MoS 2 @PEDOT/rGO are fabricated through a microwave-irradiated thermal reduction process. • The conductivity and polarization relaxation of hybrids can be regulated effectively. • The ultra-wide EAB of 7.04 GHz for S3 can be obtained. In consideration of the growing electromagnetic wave (EMW) pollution and interference, it is of crucial and imperative significance to develop high-efficiency EMW absorption materials. Herein, hierarchical hybrid network of MoS 2 @poly (3, 4-ethylenedioxythiophene) (PEDOT)/reduced graphene oxide (rGO) were successfully constructed and fabricated through the combination of oxidative polymerization and microwave-irradiated thermal reduction. The original defects in graphene oxide (GO) could be in situ repaired by introducing carbon source, and the rational regulation of polarization relaxation and conductivity of composites could be achieved. Profiting from the good impedance matching, ameliorated conductivity and enhanced dipole polarization as well as interfacial polarization by introducing GO/defect-recovered rGO and conductive PEDOT, both the MoS 2 @PEDOT/GO and MoS 2 @PEDOT/rGO composites exhibited outstanding EMW absorption performances. In details, the minimum reflection loss (RL min) and effective absorption bandwidth (EAB) of MoS 2 @PEDOT/GO can reach −48.65 dB at 4.5 mm, and 6.48 GHz (11.52–18 GHz) at 2.2 mm, respectively. And the EAB of MoS 2 @PEDOT/rGO can reach 7.04 GHz (10.8–17.84 GHz) with an optimized RL min of −32.41 dB at 2.1 mm under 20 wt% filler loading. Therefore, these composites can be regarded as competitive candidates for lightweight and high-efficient EMW absorbers. [ABSTRACT FROM AUTHOR]

The hierarchical MoS 2 @PEDOT/rGO hybrid exhibited outstanding electromagnetic wave absorption performance stemming from the synergistic effect of well-matched impedance and enhanced dielectric loss. [Display omitted] • MoS 2 @PEDOT/rGO are fabricated through a microwave-irradiated thermal reduction process. • The conductivity and polarization relaxation of hybrids can be regulated effectively. • The ultra-wide EAB of 7.04 GHz for S3 can be obtained. In consideration of the growing electromagnetic wave (EMW) pollution and interference, it is of crucial and imperative significance to develop high-efficiency EMW absorption materials. Herein, hierarchical hybrid network of MoS 2 @poly (3, 4-ethylenedioxythiophene) (PEDOT)/reduced graphene oxide (rGO) were successfully constructed and fabricated through the combination of oxidative polymerization and microwave-irradiated thermal reduction. The original defects in graphene oxide (GO) could be in situ repaired by introducing carbon source, and the rational regulation of polarization relaxation and conductivity of composites could be achieved. Profiting from the good impedance matching, ameliorated conductivity and enhanced dipole polarization as well as interfacial polarization by introducing GO/defect-recovered rGO and conductive PEDOT, both the MoS 2 @PEDOT/GO and MoS 2 @PEDOT/rGO composites exhibited outstanding EMW absorption performances. In details, the minimum reflection loss (RL min) and effective absorption bandwidth (EAB) of MoS 2 @PEDOT/GO can reach −48.65 dB at 4.5 mm, and 6.48 GHz (11.52–18 GHz) at 2.2 mm, respectively. And the EAB of MoS 2 @PEDOT/rGO can reach 7.04 GHz (10.8–17.84 GHz) with an optimized RL min of −32.41 dB at 2.1 mm under 20 wt% filler loading. Therefore, these composites can be regarded as competitive candidates for lightweight and high-efficient EMW absorbers. [ABSTRACT FROM AUTHOR]

Sludge pyrolysis has become an important method of sludge recycling. Stabilizing heavy metals in sludge is key to sludge recycling. Currently, research on the co-pyrolysis of sludge and industrial waste is limited. This study aims to explore the impact and mechanism of the co-pyrolysis of sludge and CaSiO 3 (the main component of slag) and to achieve the concept of "treating waste with waste". To this end, we added different proportions of CaSiO 3 (0%, 3%, 6%, 9%, 12%, and 15%) for the co-pyrolysis with sludge, and varied the pyrolysis temperatures (300, 400, 500, 600, and 700 °C) and retention times (15, 30, 60, and 120 min) to study heavy-metal stabilization in sludge. Consequently, the optimum dosage of CaSiO 3 required for the immobilization of different heavy metals was 9% (Cu, Zn, Pb, and Cr) and 15% (Ni). The contents of Cu, Zn, Pb, Cr, and Ni in the stable state (oxidized and residual states) were 92.73%, 79.23%, 99.55%, 92.43% and 90.33% respectively. At a pyrolysis temperature of 700 °C, the steady-state proportions of Cr, Pb, and Zn were 88.12%, 90.21%, and 77.21%, respectively. At a pyrolysis temperature of 400 °C, the stable-Cu and -Ni contents were 97.21% and 99.43%, respectively. The optimal dwelling time was 15 min. The results showed that the CaSiO 3 addition weakened the O–H stretching vibration peak intensity, promoted the formation of aromatic and epoxy ring structures, and enhanced the heavy-metal immobilization. Furthermore, the CaSiO 3 decomposition during co-pyrolysis produced SiO 2 , CaO, and Ca(OH) 2 , which helped stabilize heavy metals. [Display omitted] • This is the first study on the influence and co-pyrolysis mechanism of sludge and CaSiO 3. • Co-pyrolysis with CaSiO 3 can accelerate the stabilization of heavy metals in sludge. • CaCO 3 promotes the formation of aromatic and epoxy ring structures in residues. [ABSTRACT FROM AUTHOR]

Crop residue return is an effective, eco-friendly tillage method for decreasing reactive nitrogen (Nr) losses via surface runoff. However, the associated variation in Nr characteristics and its prospective mechanisms are not well understood. We systematically evaluated the response of Nr runoff loss and N variation in standing water to the abiotic and biotic parameters of soil in a paddy field after 6 years of straw return. Five experimental treatments of different fertilization strategies in combination with straw return were tested during the rice growth season. The results indicated that under equivalent fertilizer input, long-term straw return significantly reduced Nr runoff loss by 11.5% (P < 0.05), even though the loss increased with N fertilizer addition. We report that variations in abiotic soil properties (P < 0.05) and bacterial communities (P < 0.01) were both responsible for Nr loss differences between the rice growth stages and among the tested fertilizing patterns. Soil inorganic nitrogen (r = 0.18) had a significant positive influence on Nr runoff loss, but this effect was surpassed by the overall negative influence of soil organic carbon (r = −0.43), soil pH, (r = −0.40), and bacterial community composition (r = −0.14), which was especially apparent during the tillering stage. Our results emphasize the importance of jointly considering biotic and abiotic factors in soil and standing water when characterizing the effects of long-term straw return and N addition on Nr runoff loss, which will aid in mitigating N-based agricultural non-point pollution. [Display omitted] • Reactive nitrogen (Nr) runoff loss was reduced after straw return. • Nr increased with the addition of N fertilizer. • Soil inorganic N had positive effects on Nr runoff loss. • These positive effects were surpassed by the negative effects of SOC and pH. • The reduction in Nr loss was associated with increased Proteobacteria. [ABSTRACT FROM AUTHOR]

[Display omitted] • ZnO/Fe Schottky junctions were fabricated in Fe(CN) 6 3− ligand exchange method. • Rietveld refinement was employed on analyzing heterogenous interfacial structures. • Heterointerfaces with Schottky contacts can be regarded as effective polar interfaces. • The f E of S3 reached 4.88 GHz with RL min of –33.36 dB. Various types of polycrystals have been regarded as excellent electromagnetic (EM) microwave absorbents, while differentiated heterointerfaces among grains usually manipulate conductive loss and polarization relaxation, especially interfacial polarization. Herein, polar facets that dominated the optimization of EM attenuation were clarified by carefully designing polycrystalline Schottky junctions with metal–semiconductor contacts for the first time. An ingenious ligand exchange technique was utilized to construct Zn-MOF (ZIF-L) precursors for Fe-ZnO polycrystals, in which Fe-containing Fe(CN) 6 3− etching ligand acted as metallic source in Schottky junctions. By adjusting the Schottky contacts in polycrystals, the enhanced grain boundaries mainly induced stronger interfacial polarization and affected the microcurrent lightly. This is because Schottky barriers can cause local charge accumulation on heterointerfaces for polarization relaxation. Additionally, the coexistence of Zn and O vacancies brought a lot of lattice defects and distortions for dipole polarization. Thus, optimal EM wave absorbability was obtained by polycrystals with 8 h ligand exchange and an effective absorption band reaching 4.88 GHz. This work can provide guidance for designing advanced polycrystalline EM absorption materials and also highlight the mechanism and requirement of Schottky junctions dominating polarization. [ABSTRACT FROM AUTHOR]

Soil loss is an environmental concern of global importance. Accurate simulation of soil loss in small watersheds is crucial for protecting the environment and implementing soil and water conservation measures. However, predicting soil loss while meeting the criteria of high precision, efficiency, and generalizability remains a challenge. Therefore, this study first used three machine learning (ML) algorithms, namely, random forest (RF), support vector machine (SVM), and artificial neural network (ANN) to develop soil loss models and predict soil loss rates (SLRs). These soil loss models were constructed using field observation data with an average SLR of 1756.48 t/km2 from rainfall events and small watersheds in the hilly-gully region of the Loess Plateau, China. During training, testing and generalizability stages, the average coefficients of determination from the RF, SVM, and ANN models were 0.903, 0.860, and 0.836, respectively. Similarly, the average Nash-Sutcliffe coefficients of efficiency from the RF, SVM and ANN models were 0.893, 0.791 and 0.814, respectively. These results indicated that MLs have superior predictive performance and generalizability, and broad prospects for predicting SLRs. This study also demonstrated that the RF model outperformed better than the SVM and ANN models. Therefore, the RF model was used to simulate the SLR of each small watershed in the Chabagou watershed. Our results showed the four-year (2017–2020) average annual SLR of the small watersheds ranged from 0.73 to 1.63 × 104 t/(km2∙a) in the Chabagou watershed. Additionally, the results also indicated the SLR of small watersheds under the rainstorm event with a 100-year recurrence interval was 4.4–51.3 times that of other rainfall events.Furthermore, this study confirmed that bare land was the predominant source of soil loss in the Chabagou watershed, followed by cropland land and grassland. This study helps to provide the theoretical basis for deploying soil and water conservation measures to realize the sustainable utilization of soil resources in the future. [Display omitted] • Three machine learning algorithms were first used to build soil loss models. • Random forest demonstrated the most favorable performance for soil loss modeling. • Soil loss caused by rainstorms was 4.4–51.3 times that of other rainfall events. • Bare land was the predominant source of soil loss. [ABSTRACT FROM AUTHOR]