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BLOCKCHAIN-RESEARCH AND APPLICATIONS 2024年第2期5卷 140-150页

作者： Lee, Heejung Lee, Geun-Cheol Koo, Hoon-Young Hanyang univ Sch Interdisciplinary Ind Studies 222 Wangsimni Ro Seoul 04763 South Korea Konkuk univ Coll Business Adm 120 Neungdong Ro Seoul 05029 South Korea chungnam natl univ Sch Business 99 Daehak Ro Daejeon 34134 South Korea

Non-fungible token (NFT) is a digital asset whose ownership can be validated and controlled via blockchain technology. The NFT market is a rapidly growing field, and the rarity of NFT is an essential factor that affects its price, as scarcity leads to higher demand. This study focuses on the BAYC NFT collection, which is a successful and representative collection of profile picture NFT, and analyzes how rarity affects NFT prices. This paper investigates the relationship between the rarity and price of the BAYC NFT collection using formal concept analysis (FCA) method. The results show that rarity is a major factor influencing the price of NFT and the effect is more apparent in the medium rarity range. When rarity is very high or very low, other factors become significant determinants, such as the uniqueness and appeal of NFT, and even the naturalness of NFT images. This research highlights the importance of considering rarity when assessing NFT and underscores the need for a comprehensive evaluation of NFT rarity. This study also provides valuable insights into the NFT market and can be useful for NFT investors, creators, and collectors. Furthermore, the usefulness of FCA as a tool for quantifying NFT rarity and evaluating NFT price was demonstrated.

关键词： NFT valuation Formal concept analysis Rarity

Mo2B2O2 MBene for Efficient Electrochemical CO Reduction to C2 Chemicals: Computational Exploration

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ENERGY & ENVIRONMENTAL MATERIALS 2024年第6期7卷 342-350页

作者： Zhang, Bikun Jiang, Jianwen natl univ Singapore Dept Chem & Biomol Engn Singapore 117576 Singapore

Emerging as a new class of two-dimensional materials with atomically thin layers, MBenes have great potential for many important applications such as energy storage and electrocatalysis. Toward mitigating carbon footprint, there has been increasing interest in CO2/CO conversion on MBenes, but mostly focused on C-1 products. C2+ chemicals generally possess higher energy densities and wider applications than C1 counterparts. However, C-C coupling is technically challenging because of high energy requirement and currently few catalysts are suited for this process. Here, we explore electrochemical CO reduction reaction to C-2 chemicals on Mo2B2O2 MBene via density-functional theory calculations. Remarkably, the most favorable CO-COH coupling is revealed to be a spontaneous and barrierless process, making Mo2B2O2 an efficient catalyst for C-C coupling. Among C-1 and C-2 chemicals, ethanol is predicted to be the primary product. Furthermore, by charge and bond analysis, it is unraveled that there exist significantly more unbonded electrons in the C atom of intermediate *COH than other C-1 intermediates, which is responsible for the facile C-C coupling. From an atomic scale, this work provides microscopic insight into C-C coupling process and suggests Mo2B2O2 a promising catalyst for electrochemical CO reduction to C-2 chemicals.

关键词： C-2 chemicals C-C coupling density-functional theory MBene Mo2B2O2 GENERALIZED GRADIENT APPROXIMATION CARBON-MONOXIDE ELECTROREDUCTION CONVERSION CATALYSTS INSIGHTS DESIGN SELECTIVITY EXCHANGE

Comparative study on pump frequency tuning and self-injection locking in Kerr microcomb generation

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CHINESE OPTICS LETTERS 2024年第8期22卷 081301-081301页

作者： Yu, Zhuopei Hua, Weihong Zhang, Chenxi Miao, Runlin Yin, Ke Jiang, Tian natl univ Def Technol Coll Adv Interdisciplinary Studies Changsha 410073 Peoples R China Acad Mil Sci PLA China Natl Innovat Inst Def Technol Beijing 100071 Peoples R China natl univ Def Technol Inst Quantum Sci & Technol Changsha 410073 Peoples R China

The optical frequency comb has attracted considerable interest due to its diverse applications in optical atomic clocks, ultra-low-noise microwave generation, dual-comb spectroscopy, and optical communications. The merits of large frequency spacing, high integration, and low power consumption have shown that microresonator-based Kerr optical frequency combs will become mainstream in the future. Two methods of pump frequency tuning and self-injection locking were used to obtain Kerr combs in the same silicon nitride microresonators with free spectral ranges of 50 GHz and 100 GHz. Singlesoliton combs are realized with both methods. Simplicity, pump power, spectrum bandwidth, conversion efficiency, and linewidth are compared and analyzed. Our results show that the advantages of pump frequency tuning are a wider spectrum and higher soliton power while the advantages of self-injection locking are simplicity, compactness, low cost, significant linewidth narrowing, and high conversion efficiency.

关键词： Kerr frequency comb silicon nitride frequency tuning self-injection locking soliton comb SOLITON COMB

Understanding of the Relationship between the Properties of Cu(In,Ga)Se2 Solar Cells and the Structure of Ag Network Electrodes

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ENERGY & ENVIRONMENTAL MATERIALS 2024年第6期7卷 246-253页

作者： Yoo, Hyesun Quy, Hoang Van Lee, Inpyo Jo, Seung Taek Hong, Tae Ei Kim, Junho Yoo, Dae-Hwang Shin, Jinwook Commerell, Walter Kim, Dae-Hwan Roh, Jong Wook Kyungpook natl univ Reg Leading Res Ctr RLRC Smart Energy Syst Daegu 37224 Gyeongsangbug D South Korea Kyungpook natl univ Dept Hydrogen & Renewable Energy Daegu 47922 South Korea Kyungpook natl univ Dept Nano & Adv Mat Sci & Engn Daegu 37224 Gyeongsangbug D South Korea Daegu Gyeongbuk Inst Sci & Technol DGIST Div Energy Technol Daegu 42988 South Korea Incheon natl univ Dept Phys Nano Photoelect Device Lab Incheon 22012 South Korea TH Ulm THU Prittwitzstr 10 D-89081 Ulm Germany

The relation between the structure of the silver network electrodes and the properties of Cu(In,Ga)Se2 (CIGS) solar cells is systemically investigated. The Ag network electrode is deposited onto an Al:ZnO (AZO) thin film, employing a self-forming cracked template. Precise control over the cracked template's structure is achieved through careful adjustment of temperature and humidity. The Ag network electrodes with different coverage areas and network densities are systemically applied to the CIGS solar cells. It is revealed that predominant fill factor (FF) is influenced by the figure of merit of transparent conducting electrodes, rather than sheet resistance, particularly when the coverage area falls within the range of 1.3-5%. Furthermore, a higher network density corresponds to an enhanced FF when the coverage areas of the Ag networks are similar. When utilizing a thinner AZO film, CIGS solar cells with a surface area of 1.0609 cm2 exhibit a notable performance improvement, with efficiency increasing from 10.48% to 11.63%. This enhancement is primarily attributed to the increase in FF from 45% to 65%. These findings underscore the considerable potential for reducing the thickness of the transparent conductive oxide (TCO) in CIGS modules with implications for practical applications in photovoltaic technology.

关键词： CIGS large-area solar cell metal mesh metallic network transparent electrode

An innovative inertial parameters identification method for non-cooperative space targets based on electrostatic interaction

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CHINESE JOURNAL OF AERONAUTICS 2024年第9期37卷 417-432页

作者： Jing, Heng Zheng, Zixuan Che, Dejia Yuan, Jianping Northwestern Polytech univ Natl Key Lab Aerosp Flight Dynam Xian 710072 Peoples R China Northwestern Polytech univ Sch Astronaut Xian 710072 Peoples R China

Inertial characteristics of non-cooperative targets are crucial for space capture and subsequent on-orbit servicing. Previous methods for identifying inertial parameters involve proximity operations, which are associated with the risk of collision with non-cooperative targets. This paper introduces a long-range, contactless method for identifying the inertial parameters of a noncooperative target during the pre-capture phase. Specifically, electrostatic interaction is used as an external excitation to alter the target's motion. A force estimation algorithm that uses measurements from visual and potential sensors is proposed to estimate the electrostatic interaction and eliminate the need for force sensors. Furthermore, a recursive estimation-identification framework is presented to concurrently estimate the coupled motion state, weak electrostatic interaction, and inertial parameters of the target. The simulation results show that the proposed method extends the identification distance to 170 times that of the previous method while maintaining high identification precision for all parameters.

关键词： Non-cooperative target Inertial parameters identifi- cation Electrostatic interaction Force estimation Dynamical coupling ATTITUDE-CONTROL ROBOT SATELLITE FORCES POSE

Increasing concentrations of dietary threonine, tryptophan, and glycine improve growth performance and intestinal health with decreasing stress responses in broiler chickens raised under multiple stress conditions

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ANIMAL NUTRITION 2024年第3期18卷 145-153页

作者： Kim, Hyun Woo Kim, Jong Hyuk Han, Gi Ppeum Kil, Dong Yong Chung Ang univ Dept Anim Sci & Technol Anseong 17546 South Korea Chungbuk natl univ Dept Anim Sci Cheongju 28644 South Korea

The current study aimed to compare the effects of increasing concentrations of dietary threonine (Thr), tryptophan (Trp), and glycine (Gly) on growth performance, stress biomarkers, and intestinal function in broiler chickens under multiple stress conditions. Five hundred sixty broiler chickens at 21 d old were randomly allotted to 5 treatments with 8 replicates. Birds in a positive control (PC) treatment were raised under low stock density (16.9 birds/m(2) per cage) with recommended environmental conditions, whereas birds in 4 treatments were subjected to multiple stress conditions: a cyclic heat stress of 30 +/- 0.3 degrees C for 10 h and 23 +/- 0.2 degrees C for 14 h per day with high stock density (25.3 birds/m(2) per cage). A basal diet was assigned to both PC and negative control (NC) treatments. Three additional diets were individually formulated to contain double concentrations of digestible Thr, Trp, or Gly + Ser compared with their concentrations in the basal diet. The experiment lasted for 14 d. Results showed that NC treatment had less growth performance (P < 0.001), jejunal goblet cell counts (P = 0.018), and trans-epithelial electrical resistance (TEER; P < 0.001), but greater (P = 0.026) feather corticosterone (CORT) concentrations than PC treatment. Thr treatment showed the least (P < 0.001) feed conversion ratio (FCR) among treatments under multiple stress conditions. Thr, Trp, and Gly treatments had less (P = 0.026) feather CORT concentrations, but had greater (P < 0.001) TEER than NC treatment. In conclusion, increasing concentrations of dietary Thr, Trp, or Gly improve the growth performance and intestinal health in broiler chickens with decreasing stress response under multiple stress conditions.

关键词： Broiler chicken Glycine Multiple stress Threonine Tryptophan MEAT QUALITY HEAT-STRESS BEHAVIORAL-RESPONSES OXIDATIVE STATUS SUPPLEMENTATION MICROFLORA INTEGRITY PROTEIN METABOLISM EXPRESSION

Ultrasensitive Indium Phosphide Nanomembrane Wearable Gas Sensors

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ENERGY & ENVIRONMENTAL MATERIALS 2024年第6期7卷 209-217页

作者： Wei, Shiyu Haggren, Tuomas Li, Zhe Tan, Hark Hoe Jagadish, Chennupati Tricoli, Antonio Fu, Lan Australian natl univ Res Sch Phys Ctr Excellence Transformat Meta Opt Syst Australian Res CouncilDept Elect Mat Engn Canberra ACT 2600 Australia Australian natl univ Coll Sci Res Sch Chem Nanotechnol Res Lab Canberra ACT 2600 Australia univ Sydney Fac Engn Nanotechnol Res Lab Camperdown NSW 2006 Australia

Air quality is deteriorating due to continuing urbanization and industrialization. In particular, nitrogen dioxide (NO2) is a biologically and environmentally hazardous byproduct from fuel combustion that is ubiquitous in urban life. To address this issue, we report a high-performance flexible indium phosphide nanomembrane NO2 sensor for real-time air quality monitoring. An ultralow limit of detection of similar to 200 ppt and a fast response have been achieved with this device by optimizing the film thickness and doping concentration during indium phosphide epitaxy. By varying the film thickness, a dynamic range of values for NO2 detection from parts per trillion (ppt) to parts per million (ppm) level have also been demonstrated under low bias voltage and at room temperature without additional light activation. Flexibility measurements show an adequately stable response after repeated bending. On-site testing of the sensor in a residential kitchen shows that NO2 concentration from the gas stove emission could exceed the NO2 Time Weighted Average limit, i.e., 200 ppb, highlighting the significance of real-time monitoring. Critically, the indium phosphide nanomembrane sensor element cost is estimated at <0.1 US$ due to the miniatured size, nanoscale thickness, and ease of fabrication. With these superior performance characteristics, low cost, and real-world applicability, our indium phosphide nanomembrane sensors offer a promising solution for a variety of air quality monitoring applications.

关键词： air quality monitoring flexible III-V semiconductors nanofilm ultrathin REUSE

Phase transitions and degradation/oxidation mechanisms in lead-free CsSnI3 halide perovskites

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CLEAN ENERGY 2024年第3期8卷 109-115页

作者： Ivanova, Alexandra Golikova, Margarita Luchnikov, Lev Gostishchev, Pavel Shetinin, Igor Voronov, Victor Saranin, Danila Khovaylo, Vladimir natl univ Sci & Technol MISIS NUST MISIS Leninsky Ave 4 Moscow 119049 Russia Belgorod State univ Pobedy St 85 Belgorod 308015 Russia

Halide perovskites possess ultra-low thermal conductivity and show high potential for thermoelectric devices. The chemical properties and molecular structure of halide perovskite materials are not completely stable under ambient conditions, which hinders their use in thermoelectric generators. Changes in the properties of bulk halide perovskite thermoelectrics are accompanied by partial phase transitions and surface oxidation processes. In this paper, we conducted a comprehensive study of the transport and structural properties of CsSnI3, which were pristine by vacuum melting followed by spark plasma sintering. The research results on the electrical transport of these materials revealed that exposure to an inert atmosphere does not deteriorate stability and the properties of the materials remain unchanged. However, prolonged exposure to air leads to a significant degradation of the electrical transport properties. Contrary to thin-film samples, the shift to the double perovskite structure from the perovskite one is limited to a specific surface layer. This change significantly influences the electrical transport of the material while maintaining the essential properties of both perovskite types. [GRAPHICS]

关键词： halide perovskites degradation oxidation transport properties surface STABILITY PHOTOLUMINESCENCE CONDUCTIVITY MOBILITY

Unraveling the Harmonious Coexistence of Ruthenium States on a Self-Standing Electrode for Enhanced Hydrogen Evolution Reaction

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ENERGY & ENVIRONMENTAL MATERIALS 2024年第6期7卷 303-311页

作者： Ma, Joonhee Cho, Jin Hyuk Lee, Chaehyeon Kang, Moon Sung Choi, Sungkyun Jang, Ho Won Ahn, Sang Hyun Back, Seoin Kim, Soo Young Korea univ Dept Mat Sci & Engn Seoul 02841 South Korea Sogang univ Inst Emergent Mat Dept Chem & Biomol Engn Seoul 04107 South Korea Pusan natl univ Coll Nanosci & Nanotechnol Dept Cogno Mechatron Engn Busan 46241 South Korea Seoul natl univ Res Inst Adv Mat Dept Mat Sci & Engn Seoul 08826 South Korea Chung Ang univ Sch Chem Engn & Mat Sci Seoul 06974 South Korea

The development of cost-effective, highly efficient, and durable electrocatalysts has been a paramount pursuit for advancing the hydrogen evolution reaction (HER). Herein, a simplified synthesis protocol was designed to achieve a self-standing electrode, composed of activated carbon paper embedded with Ru single-atom catalysts and Ru nanoclusters (ACP/RuSAC+C) via acid activation, immersion, and high-temperature pyrolysis. Ab initio molecular dynamics (AIMD) calculations are employed to gain a more profound understanding of the impact of acid activation on carbon paper. Furthermore, the coexistence states of the Ru atoms are confirmed via aberration-corrected scanning transmission electron microscopy (AC-STEM), X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS). Experimental measurements and theoretical calculations reveal that introducing a Ru single-atom site adjacent to the Ru nanoclusters induces a synergistic effect, tuning the electronic structure and thereby significantly enhancing their catalytic performance. Notably, the ACP/RuSAC+C exhibits a remarkable turnover frequency (TOF) of 18 s-1 and an exceptional mass activity (MA) of 2.2 A mg-1, surpassing the performance of conventional Pt electrodes. The self-standing electrode, featuring harmoniously coexisting Ru states, stands out as a prospective choice for advancing HER catalysts, enhancing energy efficiency, productivity, and selectivity. A self-standing electrode with the coexistence of Ru single atoms and Ru nanoclusters is designed for the hydrogen evolution reaction (HER). Additional acid activation process induces defects, anchoring more Ru ions on the substrate. Detailed experimental and computational investigations suggest that the electronic coupling effect between different Ru states significantly enhanced the overall HER performance. image

关键词： electrocatalysis electronic coupling effect hydrogen evolution reaction self-standing electrode CARBON ELECTROREDUCTION CATALYSTS PAPER

Wide-color-gamut, high-purity, and high-brightness thin film structural colors based on modified Fano resonant structure

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CHINESE OPTICS LETTERS 2024年第8期22卷 082601-082601页

作者： Chen, Weijie He, Zexiang Duan, Zhenzhen Yang, Jian Wang, Ning Wang, Dan Hu, Zexiong Chen, Nan Luo, Zhengqian Bu, Yikun Xiamen univ Sch Elect Sci & Engn Natl Model Microelect Coll Xiamen 361005 Peoples R China Xiamen univ Fujian Key Lab Ultrafast Laser Technol & Applicat Xiamen 361005 Peoples R China

Recently, the Fano resonance has played an increasingly important role in improving the color performance of structural colors. In this study, we further elucidate the asymmetric spectral shape generated by Fano resonance from a phase perspective and explore four distinct continuum state structures. By integrating the proposed cavity-like structure with a metal-dielectric-metal discrete state, multilayered thin-film structural colors with minimal background reflection, as low as 8%, were successfully achieved. The reflection peak of this structure exhibits a bandwidth of approximately 50 nm and reaches up to 80%, indicating heightened saturation and color brightness. Moreover, by adjusting the thickness, we effortlessly obtained a broader color gamut compared to Adobe ROB (45.2%), covering 56.7% of the CIE color space. Even adjusting a single layer can achieve a color gamut of 47.1%. In experiments, by deliberately choosing low oxygen- dependent materials, excellent ROB colors with high brightness and in high consistency with simulation results were successfully achieved. Therefore, the scheme's simple process for structural color creation, along with its excellent color performance and the ability to effectively replicate simulation characteristics makes it highly valuable in fields like anti- counterfeiting, decoration, display devices, and solar cell panels.

关键词： Fano resonance structural colors full color thin films high saturation