Engineering最新文献

Nickel-rich layered Li transition metal oxides are the most promising cathode materials for high-energy-density Li-ion batteries. However, they exhibit rapid capacity degradation induced by transition metal dissolution and structural reconstruction, which are associated with hydrofluoric acid (HF) generation from lithium hexafluorophosphate decomposition. The potential for thermal runaway during the working process poses another challenge. Separators are promising components to alleviate the aforementioned obstacles. Herein, an ultrathin double-layered separator with a 10 μm polyimide (PI) basement and a 2 μm polyvinylidene difluoride (PVDF) coating layer is designed and fabricated by combining a non-solvent induced phase inversion process and coating method. The PI skeleton provides good stability against potential thermal shrinkage, and the strong PI–PVDF bonding endows the composite separator with robust structural integrity; these characteristics jointly contribute to the extraordinary mechanical tolerance of the separator at elevated temperatures. Additionally, unique HF-scavenging effects are achieved with the formation of –CO···H–F hydrogen bonds for the abundant HF coordination sites provided by the imide ring; hence, the layered Ni-rich cathodes are protected from HF attack, which ultimately reduces transition metal dissolution and facilitates long-term cyclability of the Ni-rich cathodes. Li||NCM811 batteries (where “NCM” indicates LiNi_xCo_yMn_1−x−yO₂) with the proposed composite separator exhibit a 90.6% capacity retention after 400 cycles at room temperature and remain sustainable at 60 °C with a 91.4% capacity retention after 200 cycles. By adopting a new perspective on separators, this study presents a feasible and promising strategy for suppressing capacity degradation and enabling the safe operation of Ni-rich cathode materials.

To equip data-driven dynamic chemical process models with strong interpretability, we develop a light attention–convolution–gate recurrent unit (LACG) architecture with three sub-modules—a basic module, a brand-new light attention module, and a residue module—that are specially designed to learn the general dynamic behavior, transient disturbances, and other input factors of chemical processes, respectively. Combined with a hyperparameter optimization framework, Optuna, the effectiveness of the proposed LACG is tested by distributed control system data-driven modeling experiments on the discharge flowrate of an actual deethanization process. The LACG model provides significant advantages in prediction accuracy and model generalization compared with other models, including the feedforward neural network, convolution neural network, long short-term memory (LSTM), and attention-LSTM. Moreover, compared with the simulation results of a deethanization model built using Aspen Plus Dynamics V12.1, the LACG parameters are demonstrated to be interpretable, and more details on the variable interactions can be observed from the model parameters in comparison with the traditional interpretable model attention-LSTM. This contribution enriches interpretable machine learning knowledge and provides a reliable method with high accuracy for actual chemical process modeling, paving a route to intelligent manufacturing.

As a precise and versatile tool for genome manipulation, the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) platform holds promise for modifying fish traits of interest. With the aim of reducing transgene introgression and controlling reproduction, upscaled disease resistance and reproductive intervention in catfish species have been studied to lower the potential environmental risks of the introgression of escapees as transgenic animals. Taking advantage of the CRISPR/Cas9-mediated system, we succeeded in integrating the cathelicidin gene (As-Cath) from an alligator (Alligator sinensis) into the target luteinizing hormone (lh) locus of channel catfish (Ictalurus punctatus) using two delivery systems assisted by double-stranded DNA (dsDNA) and single-stranded oligodeoxynucleotides (ssODNs), respectively. In this study, high knock in (KI) efficiency (22.38%, 64/286) but low on-target events was achieved using the ssODN strategy, whereas adopting a dsDNA as the donor template led to an efficient on-target KI (10.80%, 23/213). The on-target KI of As-Cath was instrumental in establishing the lh knockout (LH^–_As-Cath⁺) catfish line, which displayed heightened disease resistance and reduced fecundity compared with the wild-type (WT) sibling fish. Furthermore, administration of human chorionic gonadotropin (HCG) and luteinizing hormone-releasing hormone analogue (LHRHa) can restore the reproduction of the transgenic fish line. Overall, we replaced the lh gene with an alligator cathelicidin transgene and then administered hormone therapy to move towards complete reproductive control of disease-resistant transgenic catfish in an environmentally responsible manner. This strategy not only effectively improves consumer-valued traits but also guards against unwanted introgression, providing a breakthrough in aquaculture genetics to confine fish reproduction and prevent the establishment of transgenic or domestic genotypes in the natural environment.

Substantially glazed facades are extensively used in contemporary high-rise buildings to achieve attractive architectural aesthetics. Inherent conflicts exist among architectural aesthetics, building energy consumption, and solar energy harvesting for glazed facades. In this study, we addressed these conflicts by introducing a new dynamic and vertical photovoltaic integrated building envelope (dvPVBE) that offers extraordinary flexibility with weather-responsive slat angles and blind positions, superior architectural aesthetics, and notable energy-saving potential. Three hierarchical control strategies were proposed for different scenarios of the dvPVBE: power generation priority (PGP), natural daylight priority (NDP), and energy-saving priority (ESP). Moreover, the PGP and ESP strategies were further analyzed in the simulation of a dvPVBE. An office room integrated with a dvPVBE was modeled using EnergyPlus. The influence of the dvPVBE in improving the building energy efficiency and corresponding optimal slat angles was investigated under the PGP and ESP control strategies. The results indicate that the application of dvPVBEs in Beijing can provide up to 131% of the annual energy demand of office rooms and significantly increase the annual net energy output by at least 226% compared with static photovoltaic (PV) blinds. The concept of this novel dvPVBE offers a viable approach by which the thermal load, daylight penetration, and energy generation can be effectively regulated.

In this paper, a hybrid integrated broadband Doherty power amplifier (DPA) based on a multi-chip module (MCM), whose active devices are fabricated using the gallium nitride (GaN) process and whose passive circuits are fabricated using the gallium arsenide (GaAs) integrated passive device (IPD) process, is proposed for 5G massive multiple-input multiple-output (MIMO) application. An inverted DPA structure with a low-Q output network is proposed to achieve better bandwidth performance, and a single-driver architecture is adopted for a chip with high gain and small area. The proposed DPA has a bandwidth of 4.4–5.0 GHz that can achieve a saturation of more than 45.0 dBm. The gain compression from 37 dBm to saturation power is less than 4 dB, and the average power-added efficiency (PAE) is 36.3% with an 8.5 dB peak-to-average power ratio (PAPR) in 4.5–5.0 GHz. The measured adjacent channel power ratio (ACPR) is better than −50 dBc after digital predistortion (DPD), exhibiting satisfactory linearity.