Efficient Thermal-Stress Coupling Design of Chiplet-Based System with Coaxial TSV Array.

In this research, an efficient thermal-stress coupling design method for a Chiplet-based system with a coaxial through silicon via (CTSV) array is developed by combining the support vector machine (SVM) model and particle swarm optimization algorithm with linear decreasing inertia weight (PSO-LDIW). The complex and irregular relationship between the structural parameters and critical indexes is analyzed by finite element simulation. According to the simulation data, the SVM model is adopted to characterize the relationship between structural parameters and critical indexes of the CTSV array. Based on the desired critical indexes of the CTSV array, the multi-objective evaluation function is established. Afterwards, the structural parameters of the CTSV array are optimized through the PSO-LDIW algorithm. Finally, the effectiveness of the developed method is verified by the finite element simulation. The simulated peak temperature, peak stress of the Chiplet-based system, and peak stress of the copper column (306.16 K, 28.48 MPa, and 25.76 MPa) well agree with the desired targets (310 K, 30 MPa, and 25 MPa). Therefore, the developed thermal-stress coupling design method can effectively design CTSV arrays for manufacturing high-performance interconnect structures applied in Chiplet-based systems.

Enhanced ammonium removal on biochar from a new forestry waste by ultrasonic activation: Characteristics, mechanisms and evaluation.

The adsorption treatment of ammonium-containing wastewater has attracted significant global attention. Most enhanced adsorption methods employ chemical modification, and there are few reports on physical activation. We present a physical activation to explore whether physical ultrasound may enhance the adsorption performance and comprehensive utilisation of a new forestry waste, Caragana korshinskii was used as a feedstock to prepare activated biochar (ACB) by controlling the pyrolysis temperatures and ultrasound parameters. The optimal parameters were determined via batch adsorption of NH4+, and the adsorption characteristics were assessed by 8 kinds of models and influence experiments. Moreover, the physicochemical properties of ACB during the pyrolysis process were investigated, and the ultrasonic activation and adsorption mechanisms were discussed using multiple characterisation techniques. Additionally, the cost analysis, the safety of the ultrasonic process and disposal method also were evaluated. The results showed that the ultrasonic activation significantly enhanced the NH4+ adsorption efficiency of biochar by approximately 5 times. ACB exhibited the best performance at 500 °C with an ultrasonic activation time of 480 min, frequency of 45 kHz, and power of 700 W. The ultrasonic activation reduced the biochar ash and induced pore formation, which increased the specific surface area through cavitation corrosion and micro-acoustic flow mechanism. The NH4+ adsorption mechanisms comprised physicochemical processes, of which physical adsorption was dominant. The preparation cost of 1 kg ACB was about 0.42 US dollar, and no secondary pollution occurred in the activation process. The findings prove that ultrasonic technology is efficient and convenient for enhancing biochar adsorption performance, and thus is suitable for industrial applications and promotion.

Phosphorus recovery by core-shell γ-Al2O3/Fe3O4 biochar composite from aqueous phosphate solutions.

Biochar can act as an adsorbent for phosphate removal from water sources, which can be highly beneficial in limiting eutrophication and recycling elemental phosphorus (P). However, it is difficult to use a single biochar material to overcome problems such as low adsorption efficiency, difficulty in reuse, and secondary pollution. This study addresses these challenges using a novel core-shell structure γ-Al2O3/Fe3O4 biochar adsorbent (AFBC) with significant P uptake capabilities in terms of its high adsorption capacity (205.7 mg g-1), magnetic properties (saturation magnetization 24.70 emu g-1), and high reuse stability (91.0% removal efficiency after five adsorption-desorption cycles). The highest partition coefficient 1.04 mg g-1 µM-1, was obtained at a concentration of 322.89 µM. Furthermore, AFBC exhibited strong regeneration ability in multiple cycle trials, making it extremely viable for sustainable resource management. P removal mechanisms, i.e., electrostatic attraction and inner-sphere complexation, were explained using Fourier transform infrared (FT-IR) spectra and X-ray photoelectron spectroscopy (XPS) measurements. A surface complexation model was established by considering the formation of monodentate mononuclear and bidentate binuclear surface complexes of P to illustrate the adsorption process. Owing to its high adsorption efficiency, easy separation from water, and environmental friendliness, AFBC is a potential adsorbent for P recovery from polluted waters.

Combining infiltration holes and level ditches to enhance the soil water and nutrient pools for semi-arid slope shrubland revegetation.

Active vegetation restoration has been proposed as an effective approach for restoring degraded ecosystems. Soil water and nutrient deficits hinder slope revegetation in arid and semi-arid areas. However, few studies have discussed rainfall runoff utilization and soil nutrient conservation within the context of slope vegetation restoration. In this study, the effects of combining infiltration holes and level ditches on the soil water storage, organic matter, and total nitrogen were analyzed on the slopes of shrubland and bare land. The results showed that the combined measures significantly increased the average soil water content above the 100 cm soil layer and mitigated soil desiccation below 220 cm in the shrubland. Meanwhile, the combined measures obviously increased the soil organic matter and total nitrogen above the 60 and 40 cm soil layers in bare land and shrubland, respectively. Overall, combining infiltration holes and landscape engineering measures is an effective approach for enhancing the soil water and nutrient pools of slopes. Our findings provide an effective engineering measure to combat soil water and nutrient deficits for slope vegetation restoration in arid and semi-arid areas.

Synthesis of a novel magnetic Caragana korshinskii biochar/Mg-Al layered double hydroxide composite and its strong adsorption of phosphate in aqueous solutions.

Phosphate pollution of aquatic ecosystems is of great concern and requires the development of high-performance materials for effective pollution treatment. To realize efficient phosphate removal from aqueous solution, an easily separable magnetic (Fe3O4) Caragana korshinskii biochar/Mg-Al layered double hydroxide composite (denoted as FCB/MAC) was synthesized via two-step electro-assisted modification for the first time. Subsequently, the physical and chemical properties of FCB/MAC were characterized. Furthermore, the sorption mechanism for phosphate removal was investigated in detail. The results indicated that Fe3O4 and the Mg-Al layered double hydroxide were successfully embedded in the biochar matrix. Moreover, FCB/MAC exhibited a high phosphate adsorption capacity and excellent magnetic properties for easy recovery. The maximum phosphate sorption capacity of FCB/MAC was 252.88 mg g-1, which is much higher than the capacities of most magnetic phosphate adsorbents. In addition, the adsorption kinetics and isotherms indicated that phosphate adsorption by FCB/MAC was controlled by the pseudo-second-order kinetic model and the Langmuir-Freundlich isotherm model. The phosphate adsorption mechanism involves anion exchange, electrostatic attraction, and ligand exchange. After five adsorption-desorption cycles, the phosphate adsorption capacity of FCB/MAC was 25.71 mg g-1 with 51.43% removal efficiency and high recyclability. Thus, the composite prepared in this study is a promising adsorbent for phosphate removal from aqueous solution, and this work provides an excellent reference for constructing novel biochar-based phosphate adsorbents.

An Adaptive B-Spline Neural Network and Its Application in Terminal Sliding Mode Control for a Mobile Satcom Antenna Inertially Stabilized Platform.

The mobile satcom antenna (MSA) enables a moving vehicle to communicate with a geostationary Earth orbit satellite. To realize continuous communication, the MSA should be aligned with the satellite in both sight and polarization all the time. Because of coupling effects, unknown disturbances, sensor noises and unmodeled dynamics existing in the system, the control system should have a strong adaptability. The significant features of terminal sliding mode control method are robustness and finite time convergence, but the robustness is related to the large switching control gain which is determined by uncertain issues and can lead to chattering phenomena. Neural networks can reduce the chattering and approximate nonlinear issues. In this work, a novel B-spline curve-based B-spline neural network (BSNN) is developed. The improved BSNN has the capability of shape changing and self-adaption. In addition, the output of the proposed BSNN is applied to approximate the nonlinear function in the system. The results of simulations and experiments are also compared with those of PID method, non-singularity fast terminal sliding mode (NFTSM) control and radial basis function (RBF) neural network-based NFTSM. It is shown that the proposed method has the best performance, with reliable control precision.