Engineering最新文献

Intelligent chatbots powered by large language models (LLMs) have recently been sweeping the world, with potential for a wide variety of industrial applications. Global frontier technology companies are feverishly participating in LLM-powered chatbot design and development, providing several alternatives beyond the famous ChatGPT. However, training, fine-tuning, and updating such intelligent chatbots consume substantial amounts of electricity, resulting in significant carbon emissions. The research and development of all intelligent LLMs and software, hardware manufacturing (e.g., graphics processing units and supercomputers), related data/operations management, and material recycling supporting chatbot services are associated with carbon emissions to varying extents. Attention should therefore be paid to the entire life-cycle energy and carbon footprints of LLM-powered intelligent chatbots in both the present and future in order to mitigate their climate change impact. In this work, we clarify and highlight the energy consumption and carbon emission implications of eight main phases throughout the life cycle of the development of such intelligent chatbots. Based on a life-cycle and interaction analysis of these phases, we propose a system-level solution with three strategic pathways to optimize the management of this industry and mitigate the related footprints. While anticipating the enormous potential of this advanced technology and its products, we make an appeal for a rethinking of the mitigation pathways and strategies of the life-cycle energy usage and carbon emissions of the LLM-powered intelligent chatbot industry and a reshaping of their energy and environmental implications at this early stage of development.

The incorporation of commercial flame retardants into fiber-reinforced polymer (FRP) composites has been proposed as a potential solution to improve the latter’s poor flame resistance. However, this approach often poses a challenge, as it can adversely affect the mechanical properties of the FRP. Thus, balancing the need for improved flame resistance with the preservation of mechanical integrity remains a complex issue in FRP research. Addressing this critical concern, this study introduces a novel additive system featuring a combination of one-dimensional (1D) hollow tubular structured halloysite nanotubes (HNTs) and two-dimensional (2D) polygonal flake-shaped nano kaolinite (NKN). By employing a 1D/2D hybrid kaolinite nanoclay system, this research aims to simultaneously improve the flame retardancy and mechanical properties. This innovative approach offers several advantages. During combustion and pyrolysis processes, the 1D/2D hybrid kaolinite nanoclay system proves effective in reducing heat release and volatile leaching. Furthermore, the system facilitates the formation of reinforcing skeletons through a crosslinking mechanism during pyrolysis, resulting in the development of a compact char layer. This char layer acts as a protective barrier, enhancing the material’s resistance to heat and flames. In terms of mechanical properties, the multilayered polygonal flake-shaped 2D NKN plays a crucial role by impeding the formation of cracks that typically arise from vulnerable areas, such as adhesive phase particles. Simultaneously, the 1D HNT bridges these cracks within the matrix, ensuring the structural integrity of the composite material. In an optimal scenario, the homogeneously distributed 1D/2D hybrid kaolinite nanoclays exhibit remarkable results, with a 51.0% improvement in mode II fracture toughness (G_IIC), indicating increased resistance to crack propagation. In addition, there is a 34.5% reduction in total heat release, signifying improved flame retardancy. This study represents a significant step forward in the field of composite materials. The innovative use of hybrid low-dimensional nanomaterials offers a promising avenue for the development of multifunctional composites. By carefully designing and incorporating these nanoclays, researchers can potentially create a new generation of FRP composites that excel in both flame resistance and mechanical strength.

The prevalence of metabolic-dysfunction-associated steatotic liver disease (MASLD) is alarmingly high; it is estimated to affect up to a quarter of the global population, making it the most common liver disorder worldwide. MASLD is characterized by excessive hepatic fat accumulation and is commonly associated with comorbidities such as obesity, dyslipidemia, and insulin resistance; however, it can also manifest in lean individuals. Therefore, it is crucial to develop effective therapies for this complex condition. Currently, there are no approved medications for MASLD treatment, so there is a pressing need to investigate alternative approaches. Extensive research has characterized MASLD as a multifaceted disease, frequently linked to metabolic disorders that stem from dietary habits. Evidence suggests that changes in the gut microbiome play a fundamental role in the development and progression of MASLD from simple steatosis to steatohepatitis and even hepatocellular carcinoma (HCC). In this review, we critically examine the literature on the emerging field of gut-microbiota-based therapies for MASLD and metabolic-dysfunction-associated steatohepatitis (MASH), including interventions such as fecal microbiota transplantation (FMT), probiotics, prebiotics, short-chain fatty acids, antibiotics, metabolic pathway targeting, and immune checkpoint kinase blockade.

Wastewater surveillance (WWS) can leverage its wide coverage, population-based sampling, and high monitoring frequency to capture citywide pandemic trends independent of clinical surveillance. Here we conducted a nine months daily WWS for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from 12 wastewater treatment plants (WWTPs), covering approximately 80% of the population, to monitor infection dynamics in Hong Kong, China. We found that the SARS-CoV-2 virus concentration in wastewater was correlated with the daily number of reported cases and reached two pandemic peaks three days earlier during the study period. In addition, two different methods were established to estimate the prevalence/incidence rates from wastewater measurements. The estimated results from wastewater were consistent with findings from two independent citywide clinical surveillance programmes (rapid antigen test (RAT) surveillance and serology surveillance), but higher than the cases number reported by the Centre for Health Protection (CHP) of Hong Kong, China. Moreover, the effective reproductive number (R_t) was estimated from wastewater measurements to reflect both citywide and regional transmission dynamics. Our findings demonstrate that large-scale intensive WWS from WWTPs provides cost-effective and timely public health information, especially when the clinical surveillance is inadequate and costly. This approach also provides insights into pandemic dynamics at higher spatiotemporal resolutions, facilitating the formulation of effective control policies and targeted resource allocation.

This article reviews the anti-penetration principles and strengthening mechanisms of metal materials, ranging from macroscopic failure modes to microscopic structural characteristics, and further summarizes the micro–macro correlation in the anti-penetration process. Finally, it outlines the constitutive models and numerical simulation studies utilized in the field of impact and penetration. From the macro perspective, nine frequent penetration failure modes of metal materials are summarized, with a focus on the analysis of the cratering, compression shear, penetration, and plugging stages of the penetration process. The reasons for the formation of adiabatic shear bands (ASBs) in metal materials with different crystal structures are elaborated, and the formation mechanism of the equiaxed grains in the ASB is explored. Both the strength and the toughness of metal materials are related to the materials’ crystal structures and microstructures. The toughness is mainly influenced by the deformation mechanism, while the strength is explained by the strengthening mechanism. Therefore, the mechanical properties of metal materials depend on their microstructures, which are subject to the manufacturing process and material composition. Regarding numerical simulation, the advantages and disadvantages of different constitutive models and simulation methods are summarized based on the application characteristics of metal materials in high-speed penetration practice. In summary, this article provides a systematic overview of the macroscopic and microscopic characteristics of metal materials, along with their mechanisms and correlation during the anti-penetration and impact-resistance processes, thereby making an important contribution to the scientific understanding of anti-penetration performance and its optimization in metal materials.

Optical imaging in the second near-infrared (NIR-II; 900–1880 nm) window is currently a popular research topic in the field of biomedical imaging. This study aimed to explore the application value of NIR-II fluorescence imaging in foot and ankle surgeries. A lab-established NIR-II fluorescence surgical navigation system was developed and used to navigate foot and ankle surgeries which enabled obtaining more high-spatial-frequency information and a higher signal-to-background ratio (SBR) in NIR-II fluorescence images compared to NIR-I fluorescence images; our result demonstrates that NIR-II imaging could provide higher-contrast and larger-depth images to surgeons. Three types of clinical application scenarios (diabetic foot, calcaneal fracture, and lower extremity trauma) were included in this study. Using the NIR-II fluorescence imaging technique, we observed the ischemic region in the diabetic foot before morphological alterations, accurately determined the boundary of the ischemic region in the surgical incision, and fully assessed the blood supply condition of the flap. NIR-II fluorescence imaging can help surgeons precisely judge surgical margins, detect ischemic lesions early, and dynamically trace the perfusion process. We believe that portable and reliable NIR-II fluorescence imaging equipment and additional functional fluorescent probes can play crucial roles in precision surgery.

Underground salt cavern CO₂ storage (SCCS) offers the dual benefits of enabling extensive CO₂ storage and facilitating the utilization of CO₂ resources while contributing the regulation of the carbon market. Its economic and operational advantages over traditional carbon capture, utilization, and storage (CCUS) projects make SCCS a more cost-effective and flexible option. Despite the widespread use of salt caverns for storing various substances, differences exist between SCCS and traditional salt cavern energy storage in terms of gas-tightness, carbon injection, brine extraction control, long-term carbon storage stability, and site selection criteria. These distinctions stem from the unique phase change characteristics of CO₂ and the application scenarios of SCCS. Therefore, targeted and forward-looking scientific research on SCCS is imperative. This paper introduces the implementation principles and application scenarios of SCCS, emphasizing its connections with carbon emissions, carbon utilization, and renewable energy peak shaving. It delves into the operational characteristics and economic advantages of SCCS compared with other CCUS methods, and addresses associated scientific challenges. In this paper, we establish a pressure equation for carbon injection and brine extraction, that considers the phase change characteristics of CO₂, and we analyze the pressure during carbon injection. By comparing the viscosities of CO₂ and other gases, SCCS’s excellent sealing performance is demonstrated. Building on this, we develop a long-term stability evaluation model and associated indices, which analyze the impact of the injection speed and minimum operating pressure on stability. Field countermeasures to ensure stability are proposed. Site selection criteria for SCCS are established, preliminary salt mine sites suitable for SCCS are identified in China, and an initial estimate of achievable carbon storage scale in China is made at over 51.8–77.7 million tons, utilizing only 20%–30% volume of abandoned salt caverns. This paper addresses key scientific and engineering challenges facing SCCS and determines crucial technical parameters, such as the operating pressure, burial depth, and storage scale, and it offers essential guidance for implementing SCCS projects in China.