Unveiling the Role of Cationic Pyridine Sites in Covalent Triazine Framework for Boosting Zinc–Iodine Batteries Performance
Rechargeable Zinc–iodine batteries (ZIBs) are gaining attention as energy storage devices due to their high energy density, low-cost, and inherent safety. However, poor cycling performance of these batteries always arise from the severe leakage and shuttle effect of polyiodides (I3 – and I5 –). Herein, a novel cationic pyridine-rich covalent triazine framework (CCTF-TPMB) is developed to capture and confine iodine (I2) species via strong electrostatic interaction, making it an attractive host for I2 in ZIBs. The as-fabricated ZIBs with I2 loaded CCTF-TPMB (I2@CCTF-TPMB) cathode achieve a large specific capacity of 243 mAh g–1 at 0.2 A g–1 and an exceptionally stable cyclic performance, retaining 93.9% of its capacity over 30, 000 cycles at 5 A g–1. The excellent electrochemical performance of the ZIBs can be attributed to the pyridine-rich cationic sites of CCTF-TPMB, which effectively suppress the leakage and shuttle of polyiodides, while also accelerating conversion reaction of I2 species. Combined in situ Raman and Ultraviolet-Visible analysis, along with theoretical calculations, clearly reveal the critical role played by pyridine-rich cationic sites in boosting the ZIBs performances. This work opens up a promising pathway for designing advanced I2 cathode materials toward next-generation ZIBs and beyond.
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Fri 07 Jun 13:00: 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
- Friday 07 June 2024, 13:00-14:00
- Venue: BAS Seminar Room 330b.
- Series: British Antarctic Survey - Polar Oceans seminar series; organiser: Dr Birgit Rogalla.
Solvent‐Responsive Nonporous Adaptive Crystals Derived from Pyridinium Hydrochloride and the Application in Iodine Adsorption
Nonporous adaptive crystals (NACs) are crystalline nonporous materials that can undergo a structural adaptive phase transformation to accommodate specific guest via porous cavity or lattice voids. Most of the NACs are based on pillararenes because of their flexible backbone and intrinsic porous structure. Here we report a readily prepared organic hydrochloride of 4-(4-(diphenylamino)phenyl)pyridin-1-ium chloride (TPAPyH), exhibiting the solvent dimension-dependent adaptive crystallinity. Wherein it forms a nonporous α crystal in a solvent with larger dimensions, while forming two porous β and γ crystals capable of accommodating solvent molecules in solvent with small size. Furthermore, the thermal-induced single-crystal-to-single-crystal (SCSC) transition from the β to α phase can be initiated. Upon exposure to iodine vapor or immersion in aqueous solution, the nonporous α phase transforms to porous β phase by adsorbing iodine molecules. Owing to the formation of trihalide anion I2Clˉ within the crystal cavity, TPAPyH exhibits remarkable performance in iodine storage, with a high uptaking capacity of 1.27 g·g−1 and elevated iodine desorption temperature of up to 110 and 82 °C following the first and second adsorption stage. The unexpected adaptivity of TPAPyH inspired the design of NACs for selective adsorption and separation of volatile compound from organic small molecules.
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Planar Chlorination Engineering: A Strategy of Completely Breaking the Geometric Symmetry of Fe‐N4 Site for Boosting Oxygen Electroreduction
Introducing asymmetric elements and breaking the geometric symmetry of traditional metal-N4 site for boosting oxygen reduction reaction (ORR) are meaningful and challenging. Herein, the planar chlorination engineering of Fe-N4 site was firstly proposed for remarkably improving the ORR activity. The Fe-N4/CNCl catalyst with broken symmetry exhibited a half-wave potential (E1/2) of 0.917 V versus RHE, 49 mV and 72 mV higher than those of traditional Fe-N4/CN and commercial 20 wt% Pt/C catalysts. The Fe-N4/CNCl catalyst also had excellent stability for 25,000 cycles and good methanol tolerance ability. For Zn-air battery test, the Fe-N4/CNCl catalyst had the maximum power density of 228 mW/cm2 and outstanding stability during 150 h charge-discharge test, as the promising substitute of Pt-based catalysts in energy storage and conversion devices. The density functional theory calculation demonstrated the adjacent C-Cl bond effectively broke the symmetry of Fe-N4 site, downward shifted the d-band center of Fe, facilitated the reduction and release of OH*, and remarkably lower the energy barrier of rate-determining step. This work revealed the enormous potentials of planar chlorination engineering for boosting the ORR activity of traditional metal-N4 site by thoroughly breaking their geometric symmetry.
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A Large‐Scale Fabrication of Flexible, Ultrathin, and Robust solid Electrolyte for Solid‐State Lithium‐Sulfur Batteries
solid-state electrolytes, 3D supporting skeleton, mechanical strength, uniform Li deposition, F-enriched SEIAll-solid-state lithium metal batteries (ASSLMBs) are considered as the most promising candidates for the next-generation high-safety batteries. To achieve high energy density in ASSLMBs, it is essential that the solid-state electrolytes (SSEs) are lightweight, thin, and possess superior electrochemical stability. In this study, we propose a feasible and scalable fabrication approach to construct 3D supporting skeleton using an electro-blown spinning technique. This skeleton not only enhances the mechanical strength, but also hinders the migration of Li-salt anions, improving the lithium-ion transference number of the SSE. This provides a homogeneous distribution of Li-ion flux and local current density, promoting uniform Li deposition. As a result, based on the mechanically robust and thin SSEs, the Li symmetric cells show outstanding Li plating/stripping reversibility. Besides, a stable interface contact between SSE and Li anode has been established with the formation of a F-enriched solid electrolyte interface (SEI) layer. The solid-state Li|sulfurized polyacrylonitrile (Li|SPAN) cell achieves a capacity retention ratio of 94.0% after 350 cycles at 0.5 C. Also, the high-voltage Li|LCO cell shows a capacity retention of 92.4% at 0.5 C after 500 cycles. This fabrication approach for SSEs is applicable for commercially large-scale production and application in high-energy-density and high-safety ASSLMBs.
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Tue 21 May 11:15: Diffusion meets Nested Sampling
Sampling techniques are a stalwart of reliable inference in the physical sciences, with the nested sampling paradigm emerging in the last decade(s) as a ubiquitous tool for model fitting and comparison. Parallel developments in the field of generative machine learning have enabled advances in many applications of sampling methods in scientific inference pipelines. This work explores the synergy of the latest developments in diffusion models and nested sampling. I will review the challenges of precise model comparison in high dimension, and explore how score based generative models can provide a solution. This work builds towards a public code that can apply out of the box to many established hard problems in fundamental physics, as well as providing potential to extend precise inference to problems that are intractable with classical methods. I will motivate some potential applications at the frontiers of inference that can be unlocked with these methods.
- Speaker: David Yallup (University of Cambridge)
- Tuesday 21 May 2024, 11:15-12:00
- Venue: Coffee area, Battcock Centre.
- Series: Hills Coffee Talks; organiser: David Buscher.
Thu 23 May 14:00: BSU Seminar: "The Topological Properties of the Protein Universe" This will be a free hybrid seminar. To register to attend virtually, please click here: https://events.teams.microsoft.com/event/93edb3b5-eb5d-4d19-b30b...
Deep learning methods have revolutionised our ability to predict protein structures, allowing us a glimpse into the entire protein universe. As a result, our understanding of how protein structure drives function is now lagging behind our ability to determine and predict protein structure. Here, we describe how topology, the branch of mathematics concerned with qualitative properties of spatial structures, provides a lens through which we can identify fundamental organising features across the known protein universe. We identify topological determinants that capture global features of the protein universe, such as domain architecture and binding sites. Additionally, our analysis also identified highly specific properties, so-called topological generators, that can be used to provide deeper insights into protein structure-function and evolutionary relationships. We used our approach to determine structural, functional and disease consequences of mutations, explain differences in properties of proteins in mesophiles and thermophiles, and the likely structural and functional consequences of polymorphisms in a protein. Overall, we present a practical methodology for mapping the topology of the known protein universe at scale.
This will be a free hybrid seminar. To register to attend virtually, please click here: https://events.teams.microsoft.com/event/93edb3b5-eb5d-4d19-b30b-1526233e3c17@513def5b-df17-4107-b552-3dba009e5990
- Speaker: Christian Madsen, University of Melbourne
- Thursday 23 May 2024, 14:00-15:00
- Venue: MRC Biostatistics Unit, East Forvie Building, Forvie Site Robinson Way Cambridge CB2 0SR..
- Series: MRC Biostatistics Unit Seminars; organiser: Alison Quenault.
Tue 21 May 11:15: Diffusion meets Nested Sampling
Sampling techniques are a stalwart of reliable inference in the physical sciences, with the nested sampling paradigm emerging in the last decade(s) as a ubiquitous tool for model fitting and comparison. Parallel developments in the field of generative machine learning have enabled advances in many applications of sampling methods in scientific inference pipelines. This work explores the synergy of the latest developments in diffusion models and nested sampling. I will review the challenges of precise model comparison in high dimension, and explore how score based generative models can provide a solution. This work builds towards a public code that can apply out of the box to many established hard problems in fundamental physics, as well as providing potential to extend precise inference to problems that are intractable with classical methods. I will motivate some potential applications at the frontiers of inference that can be unlocked with these methods.
- Speaker: David Yallup
- Tuesday 21 May 2024, 11:15-12:00
- Venue: Coffee area, Battcock Centre.
- Series: Hills Coffee Talks; organiser: David Buscher.
Wearable Aptalyzer Integrates Microneedle and Electrochemical Sensing for in Vivo Monitoring of Glucose and Lactate in live Animals
Continuous monitoring of clinically relevant biomarkers within the interstitial fluid (ISF) using microneedle (MN)-based assays, has the potential to transform healthcare. This study introduces the Wearable Aptalyzer, an integrated system fabricated by combining biocompatible hydrogel microneedle (HMN) arrays for ISF extraction with an electrochemical aptamer-based biosensor for in situ monitoring of blood analytes. The use of aptamers enables continuous monitoring of a wide range of analytes, beyond what is possible with enzymatic monitoring. The Wearable Aptalyzer is used for real-time and multiplexed monitoring of glucose and lactate in ISF. Validation experiments using live mice and rat models of Type 1 Diabetes demonstrate strong correlation between the measurements collected from the Wearable Aptalyzer in ISF and those obtained from gold-standard techniques for blood glucose and lactate, for each analyte alone and in combination. The Wearable Aptalyzer effectively addresses the limitations inherent in enzymatic detection methods as well as solid MN biosensors and addresses the need for reliable and multiplexed bioanalytical monitoring in vivo.
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Thu 16 May 15:00: Towards identifying neglected, obsolete and abandoned IoT and OT devices https://cl-cam-ac-uk.zoom.us/j/97216272378?pwd=M2diTFhMTnppckJtNWhFVTBKK0REZz09
The rapid adoption of Internet of Things (IoT) and Operational Technology (OT) devices to control systems remotely has introduced significant cyber-security challenges. Attackers have compromised millions of such devices over the years, exploiting their lack of management and weak cyber-security. In this paper, we examine cyber-security issues of neglected, obsolete, and abandoned IoT and OT devices exposed to the Internet. The core of our work focuses on identifying these devices using common scanning tools to find indicators of vulnerabilities and misconfigurations. Moreover, we present an analysis of our Internet-wide scans during a period of two weeks targeting security issues in 8 IoT and OT protocols: MQTT , CoAP, XMPP , Modbus, OPC UA , RTPS, DNP3 and BACnet. We observed over 1 million addresses exposing one or more of these services, of which 675,896 appear vulnerable or misconfigured. Lastly, we examine the IP reputation of the vulnerable devices and show that 7,424 were reported at least once.
https://cl-cam-ac-uk.zoom.us/j/97216272378?pwd=M2diTFhMTnppckJtNWhFVTBKK0REZz09
- Speaker: Ricardo Yaben, Technical University of Denmark (DTU)
- Thursday 16 May 2024, 15:00-16:00
- Venue: FW11.
- Series: Computer Laboratory Systems Research Group Seminar; organiser: Ryan Gibb.
Mon 27 May 14:00: Title to be confirmed
Abstract not available
- Speaker: Christoph Kehle, ETH Zurich
- Monday 27 May 2024, 14:00-15:00
- Venue: MR13.
- Series: Partial Differential Equations seminar; organiser: Amelie Justine Loher.
Mon 20 May 14:00: Coercive Hamilton-Jacobi equations: equivalent boundary conditions and new uniqueness results.
In this talk, I will report on recent works joint with N. Forcadel and R. Monneau about Hamilton-Jacobi equations posed on domains. The equation is of evolution type, that is to say the solution depends on time and space, and the Hamiltonian is coercive but not necessarily convex. We will see that different boundary conditions can lead to the same weak solutions.
- Speaker: Cyril Imbert, ENS Rue d'Ulm, CNRS
- Monday 20 May 2024, 14:00-15:00
- Venue: MR13.
- Series: Partial Differential Equations seminar; organiser: Amelie Justine Loher.
Thu 16 May 15:00: Towards identifying neglected, obsolete and abandoned IoT and OT devices
The rapid adoption of Internet of Things (IoT) and Operational Technology (OT) devices to control systems remotely has introduced significant cyber-security challenges. Attackers have compromised millions of such devices over the years, exploiting their lack of management and weak cyber-security. In this paper, we examine cyber-security issues of neglected, obsolete, and abandoned IoT and OT devices exposed to the Internet. The core of our work focuses on identifying these devices using common scanning tools to find indicators of vulnerabilities and misconfigurations. Moreover, we present an analysis of our Internet-wide scans during a period of two weeks targeting security issues in 8 IoT and OT protocols: MQTT , CoAP, XMPP , Modbus, OPC UA , RTPS, DNP3 and BACnet. We observed over 1 million addresses exposing one or more of these services, of which 675,896 appear vulnerable or misconfigured. Lastly, we examine the IP reputation of the vulnerable devices and show that 7,424 were reported at least once.
- Speaker: Ricardo Yaben, Technical University of Denmark (DTU)
- Thursday 16 May 2024, 15:00-16:00
- Venue: FW11.
- Series: Computer Laboratory Systems Research Group Seminar; organiser: Ryan Gibb.
Fri 17 May 12:00: The intersection of Interpretability and Fairness
A survey of methods of interpretability of neural networks: from gender bias mitigation to interpreting BERT embeddings in a psycholinguistic manner.
Bio:
Giuseppe Attanasio is a postdoctoral researcher affiliated with the Milan Natural Language Processing (MilaNLP) Lab at Bocconi University. His research primarily focuses on large-scale neural architectures for Natural Language Processing.
Attanasio has contributed to various research projects and publications in the field of NLP . Notably, he has worked on topics such as automatic misogyny identification, benchmarking post-hoc interpretability approaches for transformer-based models, and entropy-based attention regularization for bias mitigation. His work often involves the development and deployment of NLP algorithms to address real-world problems .
- Speaker: Giuseppe Attanasion, Milan NLP
- Friday 17 May 2024, 12:00-13:00
- Venue: https://cl-cam-ac-uk.zoom.us/j/4361570789?pwd=Nkl2T3ZLaTZwRm05bzRTOUUxY3Q4QT09&from=addon .
- Series: NLIP Seminar Series; organiser: Richard Diehl Martinez.
Deterministic Fabrication and Quantum‐Well Modulation of Phase‐Pure 2D Perovskite Heterostructures for Encrypted Light Communication
Deterministic integration of phase-pure Ruddlesden-Popper (RP) perovskites has great significance for realizing functional optoelectronic devices. However, precise fabrications of artificial perovskite heterostructures with pristine interfaces and rational design over electronic structure configurations remain a challenge. Here, the controllable synthesis of large-area ultrathin single-crystalline RP perovskite nanosheets and the deterministic fabrication of arbitrary 2D vertical perovskite heterostructures are reported. The 2D heterostructures exhibit intriguing dual-peak emission phenomenon and dual-band photoresponse characteristic. Importantly, the interlayer energy transfer behaviors from wide-bandgap component (WBC) to narrow-bandgap component (NBC) modulated by comprising quantum wells are thoroughly revealed. Functional nanoscale photodetectors are further constructed based on the 2D heterostructures. Moreover, by combining the modulated dual-band photoresponse characteristic with double-beam irradiation modes, and introducing an encryption algorithm mechanism, a light communication system with high security and reliability is achieved. This work can greatly promote the developments of heterogeneous integration technologies of 2D perovskites, and could provide a competitive candidate for advanced integrated optoelectronics.
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Fri 07 Jun 12:00: Title to be confirmed
Abstract not available
- Speaker: Carina Kauf
- Friday 07 June 2024, 12:00-13:00
- Venue: SS03, William Gates Building. Zoom link: https://cl-cam-ac-uk.zoom.us/j/4361570789?pwd=Nkl2T3ZLaTZwRm05bzRTOUUxY3Q4QT09&from=addon .
- Series: NLIP Seminar Series; organiser: Richard Diehl Martinez.
Fri 14 Jun 12:00: Title to be confirmed
Abstract not available
- Speaker: Sabri Eyuboglu
- Friday 14 June 2024, 12:00-13:00
- Venue: FW26, William Gates Building. Zoom link: https://cl-cam-ac-uk.zoom.us/j/4361570789?pwd=Nkl2T3ZLaTZwRm05bzRTOUUxY3Q4QT09&from=addon .
- Series: NLIP Seminar Series; organiser: Richard Diehl Martinez.
Enhancing the reaction kinetics and structural stability of high-voltage LiCoO2 via polyanionic species anchoring
DOI: 10.1039/D4EE00726C, PaperWei Zheng, Gemeng Liang, Hao Guo, Jingxi Li, Jinshuo Zou, Jodie Yuwono, Hongbo Shu, Shilin Zhang, Vanessa K Peterson, Bernt Johannessen, Lars Thomsen, Wenbin Hu, Zaiping Guo
Increasing the charging voltage to 4.6 V directly enhances battery capacity and energy density of LiCoO2 cathodes for lithium-ion batteries. However, issues of the activated harmful phase evolution and surface...
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Fri 24 May 12:00: Title to be confirmed
Abstract not available
- Speaker: Tim Rocktäschel
- Friday 24 May 2024, 12:00-13:00
- Venue: FW26, William Gates Building. Zoom link: https://cl-cam-ac-uk.zoom.us/j/4361570789?pwd=Nkl2T3ZLaTZwRm05bzRTOUUxY3Q4QT09&from=addon .
- Series: NLIP Seminar Series; organiser: Richard Diehl Martinez.
Fri 24 May 12:00: Title to be confirmed
Abstract not available
- Speaker: Tim Rocktäschel
- Friday 24 May 2024, 12:00-13:00
- Venue: FW26, William Gates Building. Zoom link: https://cl-cam-ac-uk.zoom.us/j/4361570789?pwd=Nkl2T3ZLaTZwRm05bzRTOUUxY3Q4QT09&from=addon .
- Series: NLIP Seminar Series; organiser: Richard Diehl Martinez.