Journals
2025 EN
Wang Caiyue · Zhang Yingzheng · Zhao Fang
+2 more
Abstract The electrocatalytic reduction of carbon dioxide (CO 2 RR) to valuable chemical feedstocks using renewable electricity is a promising approach to circumventing climate change due to the overuse of fossil energy. However, the most critical mission is to design high active and economical electrocatalysts. Metal phthalocyanine (MPc)‐based electrocatalysts have attracted extensive research due to their well‐defined active sites and flexible structural tunability. Specifically, the structural features of MPcs are first introduced and then summarize the different catalytic mechanisms for different CO 2 RR products. Importantly, the two main modification strategies of axial and horizontal modulation of MPc‐based electrocatalysts are highlighted and systematically summarized. Furthermore, the selectivity of different MPc‐based electrocatalysts for CO 2 RR products is summarized. Finally, challenges and expectations of MPc‐based electrocatalyst design and selection are proposed. This article aims to present a comprehensive overview of MPc‐based electrocatalysts, expecting to further inspire the development of MPc‐based electrocatalysts and provide new ideas for the rational design of efficient electrocatalysts.
Journals
2025 EN
Erickson Samuel S. · Arteaga Jorge · VanSant Kaitlyn T.
+6 more
Abstract This study investigates how sustained low Earth orbit (LEO) exposure affects metal halide perovskite (MHP) thin films and perovskite solar cells (PSCs). It examines samples deployed on the Materials International Space Station Experiment (MISSE) 15 and 16 missions. Five methylammonium lead iodide (MAPI) thin films are deployed on MISSE‐16, each with distinct UV filters to selectively attenuate AM0 spectral bands. While post‐flight optical analysis reveals that the least UV‐exposed film exhibits the highest emission and lowest non‐radiative recombination rate, no clear correlation is observed among the rest, and all MAPI films maintained excellent integrity throughout the mission. MISSE‐15 deployed eight PSCs with diverse structures, MHP compositions, and contact materials. Post‐flight analysis reveals stable, highly emissive MHPs, but damaged contacts due to ion migration, which caused loss of electrical response. The MISSE missions demonstrate MHPs’ suitability for space applications, while highlighting the need for improved interfacial layers and contact materials to enhance charge carrier mobility, prevent ion migration, and improve charge carrier extraction efficiency.
Journals
2025 EN
Bi Huasheng · Wang Zhaopeng · Sheng Hongwei
+10 more
Abstract Accurate spatiotemporal tracking of in vivo hydrogen peroxide (H 2 O 2 ) flux is pivotal for deciphering pathological mechanisms and guiding precision therapeutics of various diseases. While traditional assays offer accuracy and selectivity, they rely on complex sample handling or are built with rigid and permanent materials, leading to limited temporal resolution and/or requiring secondary surgical retrieval of the implants. Herein, a wireless sensing system based on the flexible and bioresorbable electrochemical sensor is reported for continuous dynamic monitoring of H 2 O 2 in vivo. The Pt‐decorated MoO 3‐ x nanozyme enables a high‐performance H 2 O 2 sensor with a low detection limit (0.26 µ m ), sustained catalytic stability (80 h), and robust anti‐interference characteristics. Density functional theory calculations reveal the catalytic enhancement mechanism of H 2 O 2 decomposition kinetics by the synergistic effect between oxygen vacancies and Pt. The detection capability of the system is demonstrated by monitoring H 2 O 2 levels in vivo during inflammation and intervention. After completing the mission, the sensor can be fully bioresorbed in the body, avoiding secondary surgical removal. This breakthrough technology establishes a personalized paradigm for redox monitoring in precision medicine.
Journals
2025 EN
Rouanet Louis · Salter Alexander William
Abstract Since the 2008 financial crisis, the Federal Reserve has expanded its objectives beyond the traditional scope of monetary policy. It directly allocates credit, incorporates inequality considerations into its employment goals, and seems prepared to involve itself in climate change policy. In response to these developments, we make three elementary but often overlooked points. First, the Fed has engaged in mission creep since its earliest days. Second, mission creep has intensified since the financial crisis due to increases in both the supply of and demand for central bank activism. We argue that the floor system and accompanying unconventional monetary policies reduced the cost of mission creep. Third, we explain the likely negative consequences of mission creep. These have three causes: (1) mission creep increases the scope of credible commitment problems, (2) novel policies suffer from major knowledge problems, and (3) since those policies make the Fed's activities harder to monitor, it becomes costlier to discipline the central bank. The results are a greater scope for regulatory capture, bureaucratic incompetence, and rent‐seeking.
Journals
2025 EN
Singh Aditya · Szajnfarber Zoe
Abstract Complex engineered systems face protracted design cycles and indefinite lifetimes, leading to discrepancies between expected and actual operating conditions. The field of design for changeability has focused on developing strategies to cope with these discrepancies. Literature has implicitly assumed that future changes can be predicted by system designers, but this assumption does not match observed reality. Often, systems must be modified in unexpected ways to maintain value, limiting the usefulness of standard change mechanisms. To understand how unexpected changes are implemented in practice, we studied the C‐130, a setting where one platform performed many missions, and close air support in Desert Storm, a setting where many platforms performed one mission. Through this examination, we find that excess and operator change are key mechanisms for changeability that have been largely ignored by literature. Excess can enable additions to systems without having to remove or swap subsystems out. It is also a critical enabler of modular changes during the operational phase. Operator changes are non‐form changes driven by system users who change how their systems are used to gain new capabilities rather than relying on changes to the form of the system. This paper also studies the relationship between these mechanisms to shed light on how changeability is achieved in practice, building the foundation for future work to study tradeoffs of implementing valuable excess during design.
Journals
2025 EN
Zhang Yutong · Ye Dong · Wei Cheng
+1 more
Abstract With the increasing complexity of space missions due to technological advancements, model‐based systems engineering (MBSE) has become a new paradigm for systems engineering (SE), providing a more formal and accurate system engineering process while reducing costs. However, MBSE does not offer a comprehensive approach for effective system function design. This study introduces a conceptual design approach that integrates axiomatic design (AD) and design structure matrix (DSM) into the MBSE paradigm and applies it to functional and logical design. The research focuses on utilizing the design knowledge encapsulated by system models to facilitate the development of new systems. System models have the potential to bridge different design domains in AD, reveal implicit associations, and offer functional and structural analysis capabilities. To validate our approach, we conducted a case study on an Emergency Response Remote Sensing mission system. This case study demonstrates that our proposed methodology lends formality to traditional AD by deriving AD matrices and DSMs from a system model, thereby enhancing the system's structure while curtailing elemental alterations during iterative design processes. The novelty of this research lies in realizing the integration of traditional design theory with the model paradigm of SE, leading to an effective design solution during the functional and logical design stages.
Journals
2025 EN
Tang Hui · Wang Lizhi · Sun Yaning
+2 more
ABSTRACT In practice, when an unmanned aerial vehicle (UAV) swarm is not executing a mission, its UAVs will be stored as inventory. To ensure that the UAV swarm can be quickly deployed when needed, it is necessary to assess and predict its storage state. Due to the flexible configuration of UAV swarms and the complex factors that affect them during storage, existing storage state indicators and prediction methods cannot meet the requirements of UAV swarm storage. In order to address these issues, a UAV swarm storage availability prediction method based on agent‐based simulation (ABS) is proposed. Considering the degradation of health status, maintenance, support, and other factors during the storage period of UAVs, a UAV swarm storage state measurement metric that covers the storage cycle is proposed. Based on this metric, a UAV swarm storage availability model is established. Then, considering the dynamic adaptability and internal complex interactions of UAV swarms, the ABS is used to realize the modeling and prediction of UAV swarm storage availability. Finally, a UAV swarm rescue case is used to illustrate its scientific validity and accuracy. Therefore, this study offers a scientific and efficient method for measuring the availability of UAV swarms, providing valuable insights for rapid response and decision‐making during the transition from storage to deployment. It also presents a viable approach for availability modeling and prediction in complex, emergent swarm systems.
Journals
2025 EN
Chen Jie · Zha Dongshan · Gao Ke
+3 more
ABSTRACT The civil aviation material support system ensures that civil aircraft receive timely and reliable aviation material support during operation. To meet the demand for a standardized architecture design for such system and resolve issues related to the lack of synergy and integration in traditional civil aviation material support system, this study proposes a model based system modeling approach. Using the Department of Defense Architecture Framework (DoDAF) in conjunction with model based systems engineering (MBSE), the study constructs the activity and information interactions between the modules of the civil aviation material support system. This is achieved through a system modeling sequence that includes requirement analysis, function analysis, and function modeling. Ultimately, from a systemic perspective, the study establishes a comprehensive system model by integrating elements of the aviation material support mission. This paper provides a detailed description of the civil aviation material support system, offers guidance for the personnel responsible for aviation material support tasks, and supports the efficient operation of civil aviation material support activities.
Journals
2025 EN
Hershey Paul C. · Wang MuCheng · Coston Jennifer N.
+4 more
ABSTRACT This paper presents an adaptable system for disaggregated and distributed chat communications that applies Artificial Intelligence (AI) to support time‐critical battlespace environments. In such environments, operators may have dozens of chat conversations ongoing simultaneously. Although some of these messages are sorted according to keywords to help the operators better prioritize them, these keywords are subject to typing errors and other corruptions that may lead to the operator missing key decision‐making information. Considering the present expansion of the battlespace to include multimission and multidomain, the number of chat sessions is greatly increasing. The challenge for mission engineering in this environment is how to reduce and prioritize the vastly expanding collection of chat messages so that operators focus only on those chat messages that are most critical to meeting mission success and to do so accurately and dynamically. The approach presented here introduces a real‐time tasking capability within a fully autonomous adaptable system for Disaggregated Distributed AI Chat Enablement (D2ACE) to support mission engineering. D2ACE applies AI/ML techniques to correct spelling, typos, and other corruptions in chat messages; to adapt to recognize uncommon language formats; and to prioritize and reduce the quantity of chat messages to only those relevant to specific commander's objectives and intent for the mission. D2ACE accomplishes these goals while maintaining security at a high level such that only authorized individuals have access to their respective relevant chat messages.
Journals
2025 EN
Maleki Elaheh · Christofi Nikolena · Fischer Nils
+3 more
ABSTRACT Systems engineering (SE) is increasingly centered on advancing from model‐based systems engineering (MBSE) to semantic‐based systems engineering (SBSE) and further integrating Digital Twin technologies. This evolution is driven by the development and use of ontologies, which provide the flexibility needed to address key challenges in MBSE, such as resolving semantic ambiguities and improving data exchange. The European Space Agency (ESA) exemplifies this shift, with numerous initiatives to improve cross‐disciplinary collaboration and data integration, positioning SE at the heart of these efforts. By incorporating modular domain ontologies and embracing semantic technologies, ESA is driving new collaborative design capabilities within SE. This paper reviews the critical role of semantic approaches in empowering SE practices and delves into their application, benefits, and future research directions. Key ESA initiatives are highlighted, alongside a demonstration of a mission that simulates this approach on a small scale.