Nanoscience News (<front>)

Abstract

The sluggish kinetics for anodic oxygen evolution reaction (OER) and insufficient catalytic performance over the corresponding Ir-based catalysts are still enormous challenges in proton exchange membrane water electrolyzer (PEMWE). Herein, we report that KIr4O8 nanowires anode catalyst with more exposed active sites and rich hydroxyl achieves a current density of 1.0 A/cm2 at 1.68 V and possesses excellent catalytic stability with 1230 h in PEMWE. Combining in situ Raman spectroscopy and differential electrochemical mass spectroscopy results, we propose the modified adsorbate evolution mechanism that rich hydroxyl in the inherent structure of KIr4O8 nanowires directly participates in the catalytic process for favoring the OER. Density functional theory calculation results further suggest that the enhanced proximity between Ir (d) and O (p) band center in KIr4O8 can strengthen the covalence of Ir-O, facilitate the electron transfer between adsorbents and active sites, and decrease the energy barrier of rate-determining step from OH* to O* during the OER.

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Changing fast and slow: Hydrographic variability along the West Antarctic Peninsula Shelf during the recent sea ice extremes

Antarctic sea ice extent has been anomalously low since 2016, and reached extreme circumpolar minima in 2022/23. The causes of this change are the subject of lively scientific debate, including the relative roles of atmospheric and ocean processes in modulating sea ice evolution. The role of the ocean is particularly challenging to address due to the lack of sustained oceanographic data under the ice. Here, we examine the ocean’s response and potential role in the extreme sea ice minima using data collected by the Palmer Long-Term Ecological Research program and BAS along the West Antarctic Peninsula (WAP). This region has undergone dramatic change during many decades, including atmospheric and deep ocean warming, glacier retreat, and sea ice loss even prior to the most recent minima. Our observations show the extreme sea ice minimum followed after sustained wind anomalies that modulate ice advection, and occurred as the upper ocean stratification that typically prevents the ventilation of warm Circumpolar Deep Water to the surface broke down. We also show that this event reverted decades of upper-ocean change along the WAP .

• Speaker: Carlos Moffat, University of Delaware
• Wednesday 15 May 2024, 14:00-15:00
• Venue: BAS Seminar Room 1; zoom.
• Series: British Antarctic Survey - Polar Oceans seminar series; organiser: Dr Birgit Rogalla.

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Statistics Clinic Easter 2024 IV

This free event is open only to members of the University of Cambridge (and affiliated institutes). Please be aware that we are unable to offer consultations outside clinic hours.

If you would like to participate, please sign up as we will not be able to offer a consultation otherwise. Please sign up through the following link: https://forms.gle/1vhZCfGJH9QTcjPE8. Sign-up is possible from May 30th midday until June 3rd midday or until we reach full capacity, whichever is earlier. If you successfully signed up, we will confirm your appointment by June 5th midday.

• Speaker: MR12 at the CMS
• Wednesday 05 June 2024, 16:30-18:00
• Venue: MR12.
• Series: Cambridge Statistics Clinic; organiser: Manuel Müller.

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Energy Environ. Sci., 2024, Accepted Manuscript
DOI: 10.1039/D4EE01139B, PaperYiyuan Yang, Zhe Jia, Qianqian Wang, Yujing Liu, Ligang Sun, Bo Sun, Juan Kuang, Shoujun Dai, Jianguo He, Sida Liu, Lunbo Duan, Hongjian Tang, Lai Chang Zhang, Jamie J. Kruzic, Jian Lu, Baolong Shen
Electrocatalytic hydrogen production plays an essential role in generating eco-friendly fuels for energy storage and transportation within a sustainable energy framework. High-entropy alloys (HEAs), with their abundant compositional variety, significantly...
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Energy Environ. Sci., 2024, Accepted Manuscript
DOI: 10.1039/D4EE00822G, Review ArticleShuhao Zou, Yan Yang, Jiarui Wang, Xuanyi Zhou, Xuanhong Wan, Min Zhu, Jun Liu
The practical application of commercialized lithium-ion batteries (LIBs) currently faces challenges due to using liquid electrolytes (LEs), including limited energy density and insufficient safety performance. The combined application of solid-state...
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Energy Environ. Sci., 2024, Advance Article
DOI: 10.1039/D4EE01008F, PaperZhengzhe Wu, Haoyu Cai, Tong Wu, Jiayi Xu, Zhenyue Wang, Hongqiang Du, Juan Zhao, Fuzhi Huang, Yi-Bing Cheng, Jie Zhong
The tricyclic alkaloid colchicine is applied to catalyzed crystallization (CC) of high-quality α-FAPbI3 perovskite film in the one-step antisolvent-free process for high performance perovskite solar cells.
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Energy Environ. Sci., 2024, Accepted Manuscript
DOI: 10.1039/D4EE00783B, PerspectiveChang Xu, Qijun Tang, Wenguang Tu, Lu Wang
Photo-thermal catalysis, leveraging light as an energy source, has emerged as a groundbreaking approach in driving chemical reactions. This method uniquely combines photonic and phononic elements of solar energy, offering...
The content of this RSS Feed (c) The Royal Society of Chemistry

Abstract

Aqueous Zn-iodine (Zn-I2) conversion batteries with iodine redox chemistry suffers the severe polyiodide shuttling and sluggish redox kinetics, which impede the battery lifespan and rate capability. Herein, we introduce an ultrastable Zn-I2 battery based on single-atom Fe-N-C encapsulated high-surface-area carbon (HC@FeNC) as the core-shell cathode materials, which accelerate the I−/I3 −/I° conversion significantly. The robust chemical-physical interaction between polyiodides and Fe-N4 sites tightly binds the polyiodide ions and suppresses the polyiodide shuttling, thereby significantly enhancing the coulombic efficiency. As a result, the core-shell HC@FeNC cathode endows the electrolytic Zn–I2 battery with an excellent capacity, remarkable rate capability, and an ultra-long lifespan over 60000 cycles. More importantly, a practical 253 Wh kg−1 pouch cell shows good capacity retention of 84% after 100 cycles, underscoring its considerable potential for commercial Zn-I2 batteries.

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Automated Fact-Checking of Climate Change Claims with Large Language Models

This talk introduces Climinator, a novel AI-based tool designed to automate the fact-checking of climate change claims. Utilizing an array of Large Language Models (LLMs) informed by authoritative sources like the IPCC reports and peer-reviewed scientific literature, Climinator employs an innovative Mediator-Advocate framework. This design allows Climinator to effectively synthesize varying scientific perspectives, leading to robust, evidence-based evaluations. Our model demonstrates remarkable accuracy when testing claims collected from Climate Feedback and Skeptical Science.

Notably, when integrating an advocate with a climate science denial perspective in our framework, Climinator’s iterative debate process reliably converges towards scientific consensus, underscoring its adeptness at reconciling diverse viewpoints into science-based, factual conclusions. While our research is subject to certain limitations and necessitates careful interpretation, our approach holds significant potential. We hope to stimulate further research and encourage exploring its applicability in other contexts, including political fact-checking and legal domains.

Bio:

Dominik Stammbach just recently finished his PhD in Natural Language Processing at ETH Zurich and is an incoming postdoc at Princeton University in Fall 2024. Dominik’s research interests include developing NLP methods which can be applied in the context of misinformation, online safety and developing methods at the intersection NLP and climate change. Among others, he wants to detect company greenwashing, the practice of companies making generic, misleading or false claims to boost their environmental credentials.

• Speaker: Dominik Stammbach, ETH Zurich
• Friday 10 May 2024, 13:00-14:00
• Venue: Room FW11 at CL or William Gates Building or on Zoom: https://cl-cam-ac-uk.zoom.us/j/4361570789?pwd=Nkl2T3ZLaTZwRm05bzRTOUUxY3Q4QT09&from=addon .
• Series: NLIP Seminar Series; organiser: lyr24.

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Automated Fact-Checking of Climate Change Claims with Large Language Models

This talk introduces Climinator, a novel AI-based tool designed to automate the fact-checking of climate change claims. Utilizing an array of Large Language Models (LLMs) informed by authoritative sources like the IPCC reports and peer-reviewed scientific literature, Climinator employs an innovative Mediator-Advocate framework. This design allows Climinator to effectively synthesize varying scientific perspectives, leading to robust, evidence-based evaluations. Our model demonstrates remarkable accuracy when testing claims collected from Climate Feedback and Skeptical Science.

Notably, when integrating an advocate with a climate science denial perspective in our framework, Climinator’s iterative debate process reliably converges towards scientific consensus, underscoring its adeptness at reconciling diverse viewpoints into science-based, factual conclusions. While our research is subject to certain limitations and necessitates careful interpretation, our approach holds significant potential. We hope to stimulate further research and encourage exploring its applicability in other contexts, including political fact-checking and legal domains.

Bio:

Dominik Stammbach just recently finished his PhD in Natural Language Processing at ETH Zurich and is an incoming postdoc at Princeton University in Fall 2024. Dominik’s research interests include developing NLP methods which can be applied in the context of misinformation, online safety and developing methods at the intersection NLP and climate change. Among others, he wants to detect company greenwashing, the practice of companies making generic, misleading or false claims to boost their environmental credentials.

• Speaker: Dominik Stammbach, ETH Zürich
• Friday 10 May 2024, 13:00-14:00
• Venue: FW11, William Gates Building. Zoom link: https://cl-cam-ac-uk.zoom.us/j/4361570789?pwd=Nkl2T3ZLaTZwRm05bzRTOUUxY3Q4QT09&from=addon .
• Series: Energy and Environment Group, Department of CST; organiser: lyr24.

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SOPEVS: Sizing and Operation of PV-EV-Integrated Modern Homes

We address a problem that arises at the confluence of three recent trends: the popularity of storage-coupled photovoltaic (PV) systems amongst homeowners, the rapid proliferation of electric vehicles (EVs) with potential for bidirectional energy storage within PV-enabled single-family homes, and third, the surge in remote working accelerated by the Covid-19 pandemic. In this context, we explore the joint optimal sizing and operation of domestic homes while accounting for different degrees of remote working and the impact of home energy management system (HEMS) operation preferences. This task is complex due to the coupling between sizing and operation and the stochastic and non-stationary nature of solar generation, load, and EV drive cycles. We introduce SOPEVS (Sizing & Operation of PV and EV integrated Single-family homes), a novel framework formulated to tackle this multifaceted challenge. We use SOPEVS to investigate how commuting habits and choices in HEMS operation affect the sizing of domestic PV energy systems.

Our findings reveal that homeowners who predominantly work from home and possess bidirectional EVs can potentially eliminate the need for separate home storage systems, thereby substantially reducing overall system costs. We also find that configuring a HEMS to maximise charging through solar energy can achieve savings of up to 80% on total system expenditure (excluding the cost of EV), depending on the desired level of grid independence and the preferred State of Charge (SOC) of EV at the time of departure.

Bio:

Anaïs Berkes is a first-year PhD Student and Gates Scholar in the Department of Computer Science and Technology at the University of Cambridge.

• Speaker: Anaïs Berkes - Department of Computer Science and Technology, University of Cambridge
• Friday 24 May 2024, 13:00-14:00
• Venue: FW11, William Gates Building. Zoom link: https://cl-cam-ac-uk.zoom.us/j/4361570789?pwd=Nkl2T3ZLaTZwRm05bzRTOUUxY3Q4QT09&from=addon .
• Series: Energy and Environment Group, Department of CST; organiser: lyr24.

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Abstract

Realizing topological superconductivity by integrating high-transition-temperature (TC ) superconductors with topological insulators can open new paths for quantum computing applications. Here, we report a new approach for increasing the superconducting transition temperature (TConset)$( {T_C^{onset}} )$ by interfacing the unconventional superconductor Fe(Te,Se) with the topological insulator Bi-Te system in the low-Se doping regime, near where superconductivity vanishes in the bulk. The critical finding is that the TConset$T_C^{onset}$ of Fe(Te,Se) increases from nominally non-superconducting to as high as 12.5 K when Bi2Te3 is replaced with the topological phase Bi4Te3. Interfacing Fe(Te,Se) with Bi4Te3 is also found to be critical for stabilizing superconductivity in monolayer films where TConset$T_C^{onset}$ can be as high as 6 K. Measurements of the electronic and crystalline structure of the Bi4Te3 layer reveal that a large electron transfer, epitaxial strain, and novel chemical reduction processes are critical factors for the enhancement of superconductivity. This novel route for enhancing TC in an important epitaxial system provides new insight on the nature of interfacial superconductivity and a platform to identify and utilize new electronic phases.

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Abstract

In heterostructures made from polar materials, e.g., AlN-GaN-AlN, the non-equivalence of the two interfaces has long been recognized as a critical aspect of their electronic properties, in that they host different two-dimensional carrier gases. Interfaces play an important role in the vibrational properties of materials, where interface states enhance thermal conductivity and can generate unique infrared-optical activity. The non-equivalence of the corresponding interface atomic vibrations, however, has not been investigated so far due to a lack of experimental techniques with both high spatial and high spectral resolution. Herein we experimentally demonstrate the non-equivalence of AlN-(Al0.65Ga0.35)N and (Al0.65Ga0.35)N-AlN interface vibrations using monochromated electron energy-loss spectroscopy in the scanning transmission electron microscope (STEM-EELS) and employ density-functional-theory (DFT) calculations to gain insights in the physical origins of observations. We demonstrate that STEM-EELS possesses sensitivity to the displacement vector of the vibrational modes as well as the frequency, which is as critical to understanding vibrations as polarization in optical spectroscopies. The combination enables direct mapping of the non-equivalent interface phonons between materials with different phonon polarizations. The results demonstrate the capacity to carefully assess the vibrational properties of complex heterostructures where interface states dominate the functional properties.

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Elliptic units for complex cubic fields

The elliptic Gamma function—an elliptic version of the ordinary Gamma function—is a meromorphic special function in three variables that mathematical physicists have shown to satisfy modular functional equations under SL(3, Z). In this talk I will present evidence (numerical and theoretical) that products of values of this function are often algebraic numbers that satisfy explicit reciprocity laws and are related to derivatives of Hecke L-functions of cubic fields at s = 0. We will discuss the relation to Stark’s conjectures and will see that this function conjecturally allows to extend the theory of complex multiplication to complex cubic fields as envisioned by Hilbert’s 12th problem. The talk will be based on arxiv:2311.04110 and is joint work with Nicolas Bergeron and Pierre Charollois.

• Speaker: Luis García (UCL)
• Tuesday 14 May 2024, 14:30-15:30
• Venue: MR13.
• Series: Number Theory Seminar; organiser: Jef Laga.

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ALPHA Experiment (Institute of Astronomy)

This seminar is organised by the Institute of Astronomy, and will take place at the Madingley road site.

• Speaker: Speaker to be confirmed
• Tuesday 21 May 2024, 11:30-12:30
• Venue: Ryle Seminar Room.
• Series: Cavendish HEP Seminars; organiser: Dr Steve Dennis.

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Abstract

Left ventricular twist is influenced by the unique oriented structure of myocardial fibers. Replicating this intricate structural-functional relationship in an in vitro heart model remains challenging, mainly due to the difficulties in achieving a complex structure with synchrony between layers. This study introduces a novel approach through the utilization of bioprinting-assisted tissue assembly (BATA)—a synergistic integration of bioprinting and tissue assembly strategies. By flexibly manufacturing tissue modules and assembly platforms, BATA can create structures that traditional methods find difficult to achieve. This approach integrates engineered heart tissue (EHT) modules, each with intrinsic functional and structural characteristics, into a layered, multi-oriented tissue in a controlled manner. EHTs assembled in different orientations exhibit various contractile forces and electrical signal patterns. The BATA is capable of constructing complex myocardial fiber orientations within a chamber-like structure (MoCha). MoCha replicates the native cardiac architecture by exhibiting three layers and three alignment directions, and it reproduces the left ventricular twist by exhibiting synchronized contraction between layers and mimicking the native cardiac architecture. The potential of BATA extends to engineering tissues capable of constructing and functioning as complete organs on a large scale. This advancement holds the promise of realizing future organ-on-demand technology.

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Quasinormal modes on asymptotically flat spacetimes

Quasinormal modes (QNMs) are damped oscillations that play an important role in the dynamics of perturbations of stationary black hole spacetimes. They are governed by frequencies that are characteristic to the black hole under consideration, much like how the overtones of a vibrating drumhead depend on its particular shape. Although extensively featured in the physics literature for over fifty years, a clear and broadly applicable mathematical definition of QNMs on asymptotically flat spacetimes has remained elusive. In this talk, I will briefly introduce initial attempts at defining QNMs and then I will present upcoming work (with C. Warnick) on the characterisation of QNMs on general stationary and asymptotically flat spacetimes.

• Speaker: Dejan Gajic (Leipzig)
• Monday 13 May 2024, 14:00-15:00
• Venue: MR13.
• Series: Partial Differential Equations seminar; organiser: Dr Greg Taujanskas.

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Abstract

As one of the most widely used medical device, sutures face challenges related to surgical site infections (SSIs) and lack of subcutaneous traceability. In the present study, we have developed a facile and effective approach using peptide-AIE nanofibers (NFs-K18) to create fluorescent-traceable antimicrobial sutures, which have been applied to four commercially available sutures. The functionalized sutures of PGAS-NFs-K18 and PGLAS-NFs-K18 exhibited fluorescence with excellent penetration from 4 mm chicken breasts. They also demonstrated remarkable stability after 24 h of white light illumination and threading through chicken breasts 10 times. These sutures efficiently generated ROS, resulting in a significant suppression of four clinical bacteria, with the highest antimicrobial rate of nearly 100%. Moreover, the sutures exhibited favorable hemocompatibility and biocompatibility. In vivo experiments demonstrated that the optimized PGLAS-NFs-K18 suture displayed potent antimicrobial activity against MRSA, effectively inhibiting inflammation and promoting tissue healing in both skin wound and abdominal wall wound models, outperforming the commercially available Coated VICRYL® Plus Antibacterial suture. Importantly, PGLAS-NFs-K18 exhibited sensitive subcutaneous traceability, allowing for accurate in situ monitoring of its degradation. We believe that this straightforward strategy offers a new pathway for inhibiting SSIs and monitoring the status of sutures.

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Battersea Power Station: Restoring an Icon

Abstract TBC

Speaker Bio:

Sam Youdan was an undergraduate in engineering at Cambridge from 2001-2005, and joined Buro Happold as a graduate engineer in January 2006. He is now a Director in the London Structures Team, and is a Fellow of the ICE .

Since 2012, Sam has been working on the Battersea Power Station project, where he led all the heritage and heavy refurbishment design and site works, including the successful dismantling and re-construction of the award-winning chimneys.

• Speaker: Sam Youdan, Buro Happold, UK
• Friday 10 May 2024, 15:00-16:00
• Venue: CivEng Seminar Room (1-33) (Civil Engineering Building).
• Series: Engineering Department Structures Research Seminars; organiser: Sam Cocking.

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Money Management and Real Investment

We propose and analyze an equilibrium model of money management in which the asset allocation decisions of money managers affect the production decisions of firms. The model produces two main results. First, comparing the performance of money managers to that of the overall market portfolio becomes less appropriate as investors (endogenously) choose to delegate more of their money to them. Indeed, as money managers control more money, their holdings get closer to the market portfolio, making it less likely that they outperform it. Second, although money managers may be outperformed by the market portfolio after their fees are taken into account, it is optimal for investors to hire their services. This is because money managers prompt a more efficient allocation of capital, making the economy more productive and firms more valuable in the process. In fact, as we show, the presence of money managers can improve the welfare of all investors, whether or not these investors choose to delegate their investment decisions to money managers.

• Speaker: Simon Gervais (Duke)
• Thursday 16 May 2024, 12:30-13:30
• Venue: 109 - Castle Teaching Room.
• Series: Cambridge Finance Workshop Series; organiser: Cerf Admin.

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