Aiming at the construction of middle-high temperature field with lower carbon oxide emission during the in-situ combustion (ISC) process, biomass-based micro-nano combustion promoter (BIO-DES-U) was prepared using paper pulp as raw materials by deep eutectic solvent-ultrasonication method. Kinetic cell (KC) combining with combustion tube experiments were conducted to investigate the oxidation behaviors and effect of BIO-DES-U on the ISC process. It was demonstrated that the ignition temperature of BIO-DES-U ranged from 181.4 °C to 211.2 °C, which was much lower than that of heavy oil (354.2–368.8 °C). Furthermore, the activation energy (Ea) of heavy oil during the low temperature oxidation (LTO) and high temperature oxidation (HTO) processes reached up to 461.4 KJ/mol and 599.3 KJ/mol, while the Ea of BIO-DES-U in VC and residue combustion (RC) stages were only 124.8 KJ/mol and 216.6 KJ/mol. The results showed that the effect of BIO-DES-U on ISC process was varied with location and concentration. The oxygen utilization ratio and oil recovery ratio reached separately the peak values of 71.57 % and 70.85 % as the 3 % BIO-DES-U was located in T3 far away from the production well, and the molar amount of COx (CO + CO2) emissions decreased to 1.22 mol with a reduction of 8.96 % compared with blank control. In addition, the oxygen utilization ratio reached 73.86 % accompanied by a 75.08 % oil recovery ratio as the 7 % BIO-DES-U was added, and the molar amount of COx emissions decreased by 11.94–1.18 mol. This work provides significant insights into the green and efficient development of ISC.
This paper investigates a semi-open queueing network with a restricted capacity for concurrent client processing. The network nodes are modeled as multi-server systems with finite buffers, operating within a fluctuating random environment controlled by a continuous-time Markov chain. A change in the environment state triggers immediate transitions in key system parameters, including arrival process matrices (MMAP), server counts, service rates, reneging rates, and routing probabilities. The system’s dynamics are characterized by a multidimensional continuous-time Markov chain. We derive an explicit generator for this chain, enabling the calculation of the steady-state distribution. Furthermore, we provide analytical formulas for key performance measures of both the network and its individual nodes. The study includes numerical examples demonstrating how performance metrics depend on concurrent processing limits and environment transition rates, followed by a brief discussion on optimization applications.
Epoxy resin, as a critical thermosetting polymer, is widely used in electronic encapsulation and various applications due to its excellent mechanical and electrical insulating properties. However, the permanent three-dimensional cross-linked network formed upon curing renders the material diffulting in resource waste and posing challenges to sustainable development. To address this limitation, the present study employs a curing agent containing dynamic disulfide bonds-2-aminophenyl disulfide (2-AFD)-to cure bisphenol A diglycidyl ether (DGEBA), thereby establishing a cross-linked network embedded with dynamic disulfide bonds. Given the limited density of dynamic bonds achievable solely through curing agents, which results in suboptimal property retention after thermal reprocessing, this study further developed a vanillin-based epoxy resin (VOEP) incorporating dynamic imine bonds, with vanillin (VAN) employed as the primary precursor. By progressively replacing DGEBA with VOEP, the concentration of dynamic bonds within the cross-linked network is increased, significantly improving the property retention after hot-press recycling. Experimental results show that when the VOEP mass fraction reaches 60 wt%, the resulting epoxy resin exhibits outstanding overall performance: the power frequency breakdown strength reaches 61.64 kV/mm, the tensile strength is 58.25 MPa, and high thermal stability is maintained. Moreover, the material demonstrates remarkable reprocessability, with power frequency breakdown strength and tensile strength retention rates reaching 89.01% and 86.54%, respectively, after physical hot-press recycling. This exceptional recyclability provides a novel strategy and valuable reference for the green and sustainable advancement of epoxy resins in the field of electrical engineering.
The Ir(ppy)3 complex was studied by dissociative electron attachment spectroscopy (DEAS). Measurements of the lifetime of the molecular anion allowed estimation of electron affinity in the range of EALT = 0.82–0.94 eV at 465–515 K, while calculations in the density functional theory (DFT) approximation predict an underestimated value of 0.33 eV. The results are discussed in comparison with the previously studied Alq3 complex, for which EALT lies in the range of 0.9–1.02 eV determined by DEAS and molecular ion photoelectron spectroscopy, which is in good agreement with the calculated value obtained by DFT.
We report a comparative study of selenium-hyperdoped silicon layers subjected to two-step thermal annealing (TA) and pulsed-laser annealing (PLA). Structural recovery and impurity redistribution were examined by Rutherford backscattering spectrometry in random and channeling modes and optical spectroscopy. Both annealing approaches restore crystallinity and high Se substitutional incorporation (53% and 72% for TA and PLA samples, respectively). However, TA leaves a higher fraction of interstitial selenium that serves as carrier-trapping centers. Optical measurements reveal the formation of a Se-related impurity band at 1-5 mu m only in the PLA samples, whereas the TA samples exhibit merely a weak free-carrier absorption. In contrast to TA samples, PLA samples demonstrate pronounced infrared (IR) photoresponse under reverse bias. These findings underline the decisive role of dopant configuration in the optoelectronic properties of hyperdoped silicon and suggest promising opportunities for silicon-based IR photodetectors.
