[en] Highlights: • Two-stage injection using diesel blended fuel at high EGR (46%) was studied. • Blending fuels induce retarded pilot heat release and have less effect on MPRR. • Effects of injection parameters of blended fuels on emissions are similar to diesel. • Different fuels have little influence on post combustion heat release. • Small quantity post injection close to main results in better efficiency and emissions. - Abstract: The effect of two-stage injection on combustion and emission characteristics under high EGR (46%) condition were experimentally investigated. Four different fuels including pure diesel and blended fuels of diesel/gasoline, diesel/n-butanol, diesel/gasoline/n-butanol were tested. Results show that blending gasoline or/and n-butanol in diesel improves smoke emissions while induces increase in maximum pressure rise rate (MPRR). Adopting pilot injection close to main injection can effectively reduce the peak of premixed heat release rate and MPRR. However, for fuels blends with high percentage of low cetane number fuel, the effect of pilot fuel on ignition can be neglected and the improvement of MPRR is not that obvious. Pilot-main interval presents more obvious effect on smoke than pilot injection rate does, and the smoke emissions decrease with increasing pilot-main interval. A longer main-post interval results in a lower post heat release rate and prolonged combustion duration. While post injection rate has little effect on the start of ignition for post injection. The variation in fuel properties caused by blending gasoline or/and n-butanol into diesel does not impose obvious influence on post combustion. The smoke emission increases first and then declines with retard of post injection timing. Compared to diesel, the smoke emissions of blended fuels are more sensitive to the variation of post injection strategy

[en] In the modern and digital battlefield, grasping the electromagnetic power of battlefield system is the key to deciding the outcome of the war, and accurate and comprehensive electromagnetic situational awareness is of great importance. Communication protocol analysis is a prerequisite for smart jamming in non-cooperative electronic countermeasures. The design of efficient jamming strategy for synchronous or networked signals can make up for the shortcoming of insufficient jamming power, solve the problems of remote and covert jamming, greatly reduce the cost of jamming equipment and improve the survivability of battlefield. Therefore, the rapid analysis of communication signal protocol has important military application value. Traditional protocol analysis requires parameter estimation layer by layer on the communication protocol, and bitstream analysis of the protocol word can only be carried out on the premise of solving modulation pattern identification and demodulation, interweave and scrambling parameter estimation and demodulation, channel decoding parameter estimation and decoding. This analysis method has the following disadvantages: long analysis cycle, strong expert dependence and high algorithm complexity. It is difficult to meet the demand of real-time analysis of unknown and flexible electromagnetic signals. In order to solve this problem, this paper proposes an idea of fast clustering of signal protocols in the physical layer by artificial intelligence method. (paper)

[en] The high energy density of rechargeable metal (Li, Na, and Zn) batteries has garnered a lot of interest. However, the poor cycle stability and low Coulomb efficiency(CE), which are mostly brought on by side reactions and dendrite development on the metal anode, place a cap on commercialization. The rational design of electrolytes via incorporating a small dose of additives is a simple, yet effect strategy to address the above issues. The majority of additives govern uniform metal deposition and significantly improve the cycling performance of metal anodes. However, the battery is a complex system and the electrolyte affects both the anode and cathode. Complex reactions during discharge/charge process put forward higher requirements for the functionality of electrolytes, such as improving the stability of the cathode and flame retardant. Thus, multifunctional additives are necessary and have more advantages in building high-performance metal batteries. The recent developments in multifunctional additives for stable and dendrite-free Li/Na/Zn anodes are the major focus of this review. Breakthrough research on multifunctional additives toward the durable cathode and high-compatible electrolytes is also highlighted. Finally, the critical challenges and new perspectives on the optimization of electrolyte formulation via multifunctional additives are emphasized. This review will provide important insight to develop more effective electrolytes for high-performance rechargeable metal batteries. (© 2023 Wiley‐VCH GmbH)

[en] 2D semiconductors have emerged as candidates for next-generation electronics. However, previously reported 2D transistors which typically employ the gate-first process to fabricate a back-gate (BG) configuration while neglecting the thorough impact on the dielectric capping layer, are severely constrained in large-scale manufacturing and compatibility with complementary metal-oxide-semiconductor (CMOS) technology. In this study, dual-gate (DG) field-effect transistors have been realized based on wafer-scale monolayer MoS${}_2$ and the gate-last processing, which avoids the transfer process and utilizes an optimized top-gate (TG) dielectric stack, rendering it highly compatible with CMOS technology. Subsequently, the physical mechanism of TG dielectric deposition and the corresponding controllable threshold voltage (V${}_{TH}$) shift is investigated. Then the fabricated TG-devices with a large on/off ratio up to 1.7 × 10${}^9$, negligible hysteresis (≈14 mV), and favorable stability. Additionally, encapsulated TG structured photodetectors have been demonstrated which exhibit photo responsivity (R) up to 9.39 × 10${}^3$ A W${}^{-<!--\; ???\; -->1}$ and detectivity (D*) ≈2.13 × 10${}^{13}$ Jones. The result paves the way for future CMOS-compatible integration of 2D semiconductors for complex multifunctional IC applications. (© 2024 Wiley‐VCH GmbH)

[en] Lithium-sulfur (Li-S) batteries have been regarded as promising next-generation energy storage systems due to their high energy density and low cost, but their practical application is hindered by inferior long-cycle stability caused by the severe shuttle effect of lithium polysulfides (LiPSs) and sluggish reaction kinetics. This study reports a La${}_2$O${}_3$-MXene heterostructure embedded in carbon nanofiber (CNF) (denoted as La${}_2$O${}_3$-MXene@CNF) as a sulfur (S) host to address the above issues. The unique features of this heterostructure endow the sulfur host with synergistic catalysis during the charging and discharging processes. The strong adsorption ability provided by the La${}_2$O${}_3$ domain can capture sufficient LiPSs for the subsequent catalytic conversion, and the insoluble thiosulfate intermediate produced by hydroxyl terminal groups on the surface of MXene greatly promotes the rapid conversion of LiPSs to Li${}_2$S via a "Wackenroder reaction." Therefore, the S cathode with La${}_2$O${}_3$-MXene@CNF (La${}_2$O${}_3$-MXene@CNF/S) exhibits excellent cycling stability with a low capacity fading rate of 0.031% over 1000 cycles and a high capacity of 857.9 mAh g${}^{-<!--\; ???\; -->1}$ under extremely high sulfur loadings. Furthermore, a 5 Ah-level pouch cell is successfully assembled for stable cycling, which delivers a high specific energy of 341.6 Wh kg${}^{-<!--\; ???\; -->1}$ with a low electrolyte/sulfur ratio (E/S ratio). (© 2023 Wiley‐VCH GmbH)