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.

Heterogeneous catalysis remains at the core of various bulk chemical manufacturing and energy conversion processes, and its revolution necessitates the hunt for new materials with ideal catalytic activities and economic feasibility. Computational high-throughput screening presents a viable solution to this challenge, as machine learning (ML) has demonstrated its great potential in accelerating such processes by providing satisfactory estimations of surface reactivity with relatively low-cost information. This review focuses on recent progress in applying ML in adsorption energy prediction, which predominantly quantifies the catalytic potential of a solid catalyst. ML models that leverage inputs from different categories and exhibit various levels of complexity are classified and discussed. At the end of the review, an outlook on the current challenges and future opportunities of ML-assisted catalyst screening is supplied. We believe that this review summarizes major achievements in accelerating catalyst discovery through ML and can inspire researchers to further devise novel strategies to accelerate materials design and, ultimately, reshape the chemical industry and energy landscape.

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.

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.

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.

Metalenses with achromatic performance offer a new opportunity for high-quality imaging with an ultra-compact configuration; however, they suffer from complex fabrication processes and low focusing efficiency. In this study, we propose an efficient design method for achromatic microlenses on a wavelength scale using materials with low dispersion, an adequately designed convex surface, and a thickness profile distribution. By taking into account the absolute chromatic aberration, relative focal length shift (FLS), and numerical aperture (NA), microlens with a certain focal length can be realized through our realized map of geometric features. Accordingly, the designed achromatic microlenses with low-dispersion fused silica were fabricated using a focused ion beam, and precise surface profiles were obtained. The fabricated microlenses exhibited a high average focusing efficiency of 65% at visible wavelengths of 410–680 nm and excellent achromatic capability via white light imaging. Moreover, the design exhibited the advantages of being polarization-insensitive and near-diffraction-limited. These results demonstrate the effectiveness of our proposed achromatic microlens design approach, which expands the prospects of miniaturized optics such as virtual and augmented reality, ultracompact microscopes, and biological endoscopy.