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[Display omitted] Electromagnetic interference (EMI) shielding is critical in electronic applications. However, the currently available EMI shielding materials are restricted in customizability and application flexibility. Recent advances in manufacturing technologies have provided a unique path to achieve the custom creation of EMI shielding solutions. A successful example is additive manufacturing (AM), which has enabled high design freedom, efficient performance regulation, and multifunctionality simultaneously into fabricated shields, offering an opportunity to start a revolution in the field of EMI shielding. In this review, we summarize the latest advances in AM of EMI shielding materials, aiming to provide a deep understanding of the connection between raw materials, manufacturing methods, design considerations, and performances of the fabricated EMI shields. We first introduce the EMI shielding mechanism and available raw materials, subsequently focusing on the characteristics of representative AM methods and the as-created EMI shielding solutions. Based on the requirements to create application-oriented EMI shielding solutions, these methods are also critically compared. Thereafter, we present the state-of-the-art design considerations of EMI shields and examine the pivotal roles of AM in realizing the designs. We conclude by discussing future research directions, aiming at motivating the use of AM in the future developments of EMI shielding solutions. [ABSTRACT FROM AUTHOR]

Fossil fuel carbon dioxide (FFCO2) is a major source of atmospheric greenhouse gases that result in global climate change. Quantification of the atmospheric concentrations and emissions of FFCO2 is of vital importance to understand its environmental process and to formulate and evaluate the efficiency of carbon emission reduction strategies. Focusing on this topic, we summarized the state-of-the-art method to trace FFCO2 using radiocarbon (14C), and reviewed the 14CO2 measurements and the calculated FFCO2 concentrations conducted in the last two decades. With the mapped-out spatial distribution of 14CO2 values, the typical regional distribution patterns and their driving factors are discussed. The global distribution of FFCO2 concentrations is also presented, and the datasets are far fewer than 14CO2 measurements. With the combination of 14C measurements and atmospheric transport models, the FFCO2 concentration and its cross-regional transport can be well interpreted. Recent progress in inverse methods can further constrain emission inventories well, providing an independent verification method for emission control strategies. This article reviewed the latest developments in the estimation of FFCO2 and discussed the urgent requirements for the control of FFCO2 according to the current situation of climate change. [ABSTRACT FROM AUTHOR]

Highlights: Fundamental principles for designing high-performance thermally conductive graphene-based polymer composites are reviewed in detail. The reasoning behind using the preconstructed graphene 3D networks for fabricating thermally conductive composites and recent progress are discussed in-depth. Insight into the existing bottlenecks and opportunities in developing preconstructed 3D networks of graphene and their thermally conductive composites is also presented.Electronic devices generate heat during operation and require efficient thermal management to extend the lifetime and prevent performance degradation. Featured by its exceptional thermal conductivity, graphene is an ideal functional filler for fabricating thermally conductive polymer composites to provide efficient thermal management. Extensive studies have been focusing on constructing graphene networks in polymer composites to achieve high thermal conductivities. Compared with conventional composite fabrications by directly mixing graphene with polymers, preconstruction of three-dimensional graphene networks followed by backfilling polymers represents a promising way to produce composites with higher performances, enabling high manufacturing flexibility and controllability. In this review, we first summarize the factors that affect thermal conductivity of graphene composites and strategies for fabricating highly thermally conductive graphene/polymer composites. Subsequently, we give the reasoning behind using preconstructed three-dimensional graphene networks for fabricating thermally conductive polymer composites and highlight their potential applications. Finally, our insight into the existing bottlenecks and opportunities is provided for developing preconstructed porous architectures of graphene and their thermally conductive composites. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Self-sacrificial biomass-derived silica is a rising and promising approach to fabricate large metal silicates, which are practical water treatment agents ascribed for easy sedimentation and separation. However, the original biomass architecture is difficult to be maintained and utilized. Furthermore, sufficient ion diffusion pathways need to be created to satisfy massive mass transport in large bulk materials. Herein, a series of metal silicates, including cobalt silicate (CoSiO x), copper silicate, nickel silicate, iron silicate, and magnesium silicate, are synthesized from Indocalamus tessellatus leaf as the biomass-derived silica source and investigated as catalysts in sulfate-radical-based advanced oxidization processes (SR-AOPs) for the first time. Among them, CoSiO x presents an analogical sandwich structure as a leaf-derived template of micron-level size. More importantly, the interior hollow nanotubes assembled by small nanosheets provide numerous pathways for ion diffusion and remarkably promote the mass transport in such large bulk materials. Owing to the combination of the unique structure with the high reactivity of Co (II) toward peroxymonosulfate, CoSiO x exhibits excellent catalytic performance with 0.242 and 0.153 min−1 rate constants for the removal of methylene blue and phenol, respectively, which outperforms/is comparable to that of the reported nanomaterials toward organic contaminants in SR-AOPs. [ABSTRACT FROM AUTHOR]

In this paper, we report on the development of the clock-torqued rolling spring loaded inverted pendulum (CTR-SLIP) model. The new model, which adds clock-based torque control on the leg orientation of the previously developed R-SLIP model, has two advantages: first, regulating the model to follow its passive dynamic running (i.e., at a fixed point) significantly increases the model's basin of attraction; and second, formulating the model closer to the empirical robot enables the model to serve as the transient and steady-state running template of the robot as the anchor. These features enable the model/robot to perform speed transition from one fixed point profile to another, and the experimental validation confirms that the robot can successfully transition between two running speeds bidirectionally. The achievement of variable-speed running by the proposed method has a unique merit—it is purely model-based, and there is no need for further tuning, optimization, or learning processes. Regarding the robot, the proposed strategy only requires it to have simple position control to regulate its leg orientations, and there is no need for other sensory modules to provide information for feedback. [ABSTRACT FROM AUTHOR]

To ensure the safe and effective application of deep geotechnical engineering, it is necessary to establish a suitable constitutive model of the rocks in thermal environment, including geothermal energy mining, and deep geological treatment of nuclear waste and tunnel fire. A strain-softening damage model of the rocks with defect growth is established based on damage evolution. According to the change in the tangent modulus from the compression phase to the elastic stage, we established a constitutive model reflecting the nonlinearity characteristics of the compression phase. According to the change in the energy conversion, the energy consumption coefficient is introduced to describe the deformation characteristics of the rocks when the residual stress is reached. The specific physical meaning and the calculation method of the energy consumption coefficient are given to correct the shortcomings of the evolution of the damage variable. We then analyzed the relationship between parameters in the constitutive model of the rocks at high temperature and normal temperature. Based on the constitutive model of the rocks at normal temperature, we established a constitutive model reflecting the influence of high temperature. Finally, the established model fit the stress-strain curves of several kinds of the rocks at different temperatures and generated desired results. The established model can be used to describe the stress-strain curve characteristics of the rocks at different temperatures. [ABSTRACT FROM AUTHOR]

Atmospheric hazardous volatile organic compounds (HVOCs) have adverse effects on human health. Health risks derived from inhalation of HVOCs have been widely assessed in Chinese cities, however, source-specific health risk analysis has been rarely done. In this work, the five intensive campaigns for monitoring HVOCs concentrations were conducted in Nanjing between July 2018 and May 2020. These datasets were further used to assess the health risks at the receptor site. The result showed that the average HVOCs concentration was 16.7 ± 20.0 ppb with higher levels in the autumn and winter. HVOCs concentrations exhibited diurnal cycles and peaked at the daytime/nighttime rush-traffic hours. By using the observed HVOCs data, the total lifetime cancer risk (LCR T) and hazard quotient (HQ T) were estimated to be 1.23 × 10−3 and 2.3, respectively, indicating the significant cancer risk and non-cancer risk at the receptor site. 1,1,2,2-tetrachloroethane (67%) was the major species to cancer risk while 1,2-dichloropropane (40%) was the dominant compound of non-cancer risk. Positive matrix factorization (PMF) model was used to resolve the source of HVOCs into vehicle emissions (29%), chemical petroleum (19%), solvent usage (17%), biomass burning (12%), coal combustion (10%), liquefied petroleum gas (9%) and fuel evaporation (4%). By combining the health risk assessments and source apportionment results, we finally concluded that solvent usage dominated both cancer risk and non-cancer risk of exposure to HVOCs at the receptor site. Thus, how to make the control measures to reduce HVOCs emissions from solvent usage will be an important issue for decreasing health risks in this polluted city. [Display omitted] • Significant cancer risk (1.23 × 10−3) and non-cancer risk (2.3) of exposure to HVOCs were found in Nanjing. • 1,1,2,2-tetrachloroethane and 1,2-dichloropropane were the major HVOCs species to health risks in Nanjing, respectively. • Solvent usage was the dominant source to 1,1,2,2-tetrachloroethane and 1,2-dichloropropane in Nanjing. • Solvent usage was the main source to health risks in Nanjing. [ABSTRACT FROM AUTHOR]

• To improve the energy conversion performance of PFSV-EMATs, a new EMAT model is designed. • A novel hybrid surrogate-assisted multi-parameter optimization algorithm is developed to enhance the PFSV-EMATs' conversion performance. • The proposed HSM-PSO is verified, and the signal amplitude of the optimized PFSV-EMAT is improved by 12 times. In ultrasonic testing field, the design and optimization of point-focusing shear vertical waves electromagnetic acoustic transducer (PFSV-EMAT) with high energy conversion efficiency have been a challenging task. In this work, a novel multi-parameter optimization method is described to improve PFSV-EMATs' conversion performance, which integrates the newly proposed hybrid surrogate modeling (HSM) approach and particle swarm optimization (PSO) algorithm for efficient optimization. Based on the established finite element model of EMATs, the amplitudes of the displacement components at the observation point of a plate is the objective function to be maximized with five parameters pertaining to the cylindrical magnets, coaxial meander-line coils, and excitation signal, as design variables. Then, a brand-new HSM-assisted PSO algorithm is proposed and the superiority and rationality of the HSM strategy are proven. In addition, the multi-parameter optimization of PFSV-EMATs is conducted with the proposed HSM-PSO algorithm. Finally, experiments are carried out to verify the validation of optimization results, indicating that the increased signal amplitude of 12 times can be achieved by the optimized PFSV-EMAT, which has the improved signal amplitude and consistent point-focusing behavior, compared with the non-optimized one. [ABSTRACT FROM AUTHOR]