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High-member low-dimensional Sn-based perovskite solar cells

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science China Chemistry 2023年第2期66卷 459-465页

作者： Hansheng Li Zihao Zang Qi Wei Xianyuan Jiang Mingyu Ma Zengshan Xing Jingtian Wang Danni Yu Fei Wang Wenjia Zhou Kam Sing Wong Philip C.Y.Chow Yuanyuan Zhou Zhijun Ning School of Physical science and technology ShanghaiTech UniversityShanghai201210China Department of Physics Hong Kong University of Science and TechnologyHong Kong999077China Department of Mechanical Engineering The University of Hong KongHong Kong999077China Department of Physics Hong Kong Baptist UniversityHong Kong999077China

Sn-based perovskites are promising thin-film photovoltaic materials for their ideal bandgap and the eco-friendliness of Sn,but the performance of Sn-based perovskite solar cells is hindered by the short carrier diffusion length and large defect density in nominally-synthesized Sn-based perovskite *** we demonstrate that a long carrier diffusion length is achievable in quasi-2D Sn-based perovskite films consisting of high-member low-dimensional Ruddlesden-Popper(RP)phases with a preferred crystal orientation *** key to the film synthesis is the use of a molecular additive formed by phenylethylammonium cations and optimally mixed halide-pseudohalide anions,which favorably tailors the quasi-2D Sn-based perovskite crystallization *** high-member RP film structure effectively enhances device short-circuit current density,giving rise to an increased power conversion efficiency(PCE)of 14.6%.The resulting device demonstrates a near-unity shelf stability upon1,000 h in nitrogen.A high reproductivity is also achieved with a count of 50 devices showing PCEs within a narrow range from minimum 13.0%to maximum 14.6%.

关键词： Sn-based perovskite lead-free perovskite solar cells low-dimensional structure optoelectronics device

Leveraging Uncertainty for Depth-Aware Hierarchical Text Classification

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Computers, Materials & Continua 2024年第9期80卷 4111-4127页

作者： Zixuan Wu Ye Wang Lifeng Shen Feng Hu hong Yu Chongqing Key Laboratory of Computational Intelligence Chongqing University of Posts and TelecommunicationsChongqing400000China Division of Emerging interdisciplinary Areas Hong Kong University of Science and TechnologyHong Kong999077China

Hierarchical Text Classification(HTC)aims to match text to hierarchical *** methods overlook two critical issues:first,some texts cannot be fully matched to leaf node labels and need to be classified to the correct parent node instead of treating leaf nodes as the final classification ***,error propagation occurs when a misclassification at a parent node propagates down the hierarchy,ultimately leading to inaccurate predictions at the leaf *** address these limitations,we propose an uncertainty-guided HTC depth-aware model called ***,we design an early stopping strategy with uncertainty to identify incomplete matching between text and labels,classifying them into the corresponding parent node *** approach allows us to dynamically determine the classification depth by leveraging evidence to quantify and accumulate *** results show that the proposed DepthMatch outperforms recent strong baselines on four commonly used public datasets:WOS(Web of science),RCV1-V2(Reuters Corpus Volume I),AAPD(Arxiv Academic Paper Dataset),and ***,on the BGC dataset,it improvesMicro-F1 andMacro-F1 scores by at least 1.09%and 1.74%,respectively.

关键词： Hierarchical text classification incomplete text-label matching uncertainty depth-aware early stopping strategy

Design and synthesis of novel 1,3-diene bridged chiral atropoisomeric diphosphine ligands for asymmetric hydrogenation ofα-dehydro amino ketones

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science China Chemistry 2023年第10期66卷 2847-2851页

作者： Xuefeng Tan Shuang Gao Chunyan Yang Qiwei Lang Xiaobing Ding Gen-Qiang Chen Xumu Zhang Laboratory of Small Molecule Drug Discovery and Synthesis Department of ChemistrySouthern University of Science and TechnologyShenzhen 518055China Academy for Advanced interdisciplinary Studies Southern University of Science and TechnologyShenzhen 518000China Department of Chemistry City University of Hong KongHong Kong 999077China

A series of novel atropisomeric diphosphine ligands termed Tan Phos were designed and synthesized,which has a smaller bite angle compared with that of other ligands such as *** Phos showed high reactivity and enantioselectivity in the rhodiumcatalyzed asymmetric hydrogenation ofα-dehydro amino ketones,and up 99%yield and 99%ee were obtained for a wide range of chiralα-amino ketones.

关键词： diphosphine asymmetric hydrogenation chiral ligand

Synthesis and Characterization of a Novel Silver-Substituted Calcium Phosphate Cement

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Journal of Materials science & technology 2014年第7期30卷 686-691页

作者： Tao Yu Chengying Gao Jiandong Ye Ming Zhang Key Laboratory of Specially Functional Materials of Ministry of Education and School of Materials science and Engineering South China University of Technology interdisciplinary Division of Biomedical Engineering The Hong Kong Polytechnic University

Antibacterial materials play an important role in clinical application, and silver has been known to exhibit strong cytotoxicity towards a broad range of micro-organisms. In this work, the amorphous calcium phosphate with silver substitution （Ag-ACP） was synthesized by chemical precipitation method, and the valence of silver in ACP was adjusted by temperature. The processed Ag-ACP was combined with slightly acidic compounds to form new calcium phosphate cement （CPC）. Our results indicate that the valence of silver in CPC was adjusted successfully by chemical precipitation method and heat treatment. X-ray diffraction （XRD） and X-ray photoelectron spectroscopy （XPS） results demonstrated that silver ion in CPC-1 and CPC-2 existed in Ag3PO4, after heat treatment of 460℃, silver became more stable in CPC-3 and CPC-4. Silver in CPC-1 end CPC-2 exhibited better releasing property. After heat treatment at 460 ℃, the amount of silver ion released from CPC decreased significantly. Besides, the antibacterial ability of Ag-CPC was adjusted by changing the valence of silver in Ag-CPC. Depending on the low valence of silver and good silver release, CPC-1 and CPC-2 exhibited better antibacterial activity. We believe that this study will motivate the development and applications of antibacterial CPC in bone tissue regeneration.

关键词： Calcium phosphate Silver substitution Heat treatment Antimicrobial activity Escherichia coli

Influence of screw length and diameter on tibial strain energy density distribution after anterior cruciate ligament reconstruction

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Acta Mechanica Sinica 2014年第2期30卷 241-249页

作者： Jie Yao Guan-Ming Kuang Duo Wai-Chi Wong Wen-Xin Niu Ming Zhang Yu-Bo Fan Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education School of Biological Science and Medical Engineering/National Key Lab of Virtual Reality TechnologyBeihang University interdisciplinary Division of Biomedical Engineering Faculty of EngineeringThe Hong Kong Polytechnic University Shenzhen Key Laboratory for Innovative technology in Orthopaedic Trauma Department of Orthopaedics and TraumatologyThe University of Hong Kong-Shenzhen Hospital The university of hong kong Tongji university School of Medicine

Postoperative tunnel enlargement has been frequently reported after anterior cruciate ligament（ACL）*** screw,as a surgical implant in ACL reconstruction,may influence natural loading transmission and contribute to tunnel *** aims of this study are（1）to quantify the alteration of strain energy density（SED）distribution after the anatomic single-bundle ACL reconstruction;and（2）to characterize the influence of screw length and diameter on the degree of the SED alteration.A validated finite element model of human knee joint was *** screw length ranging from 20 to 30 mm with screw diameter ranging from 7 to 9 mm were *** the post-operative knee,the SED increased steeply at the extra-articular tunnel aperture under compressive and complex loadings,whereas the SED decreased beneath the screw shaft and nearby the intra-articular tunnel *** the screw length could lower the SED deprivation in the proximal part of the bone tunnel;whereas increasing either screw length or diameter could aggravate the SED deprivation in the distal part of the bone *** the elastic modulus of the screw could lower the bone SED deprivation around the *** consideration of both graft stability and SED alteration,a biodegradable interference screw with a long length is recommended,which could provide a beneficial mechanical environment at the distal part of the tunnel,and meanwhile decrease the bone-graft motion and synovial fluid propagation at the proximal part of the *** findings together with the clinical and histological factors could help to improve surgical outcome,and serve as a preliminary knowledge for the following study of biodegradable interference screw.

关键词： Anterior crucial ligament reconstruction Strain energy density Screw length Screw diameter

An ultra thin,bright,and sensitive interactive tactile display based on organic mechanoluminescence for dual-mode handwriting identification

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InfoMat 2024年第6期6卷 76-87页

作者： Tingting Hou Wenlang Li Haoyu Wang Yuantian Zheng Chaojie Chen Haoran Zhang Kai Chen Huilin Xie Xin Li Shaoshuai He Siwei Zhang Dengfeng Peng Cheng Yang Jacky W.Y.Lam Ben Zhong Tang Yunlong Zi Department of Mechanical and Automation Engineering The Chinese University of Hong KongHong Kongthe People's Republic of China Department of Chemistry Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction and Institute for Advanced StudyThe Hong Kong University of Science and TechnologyHong Kongthe People's Republic of China Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province College of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhenthe People's Republic of China Thrust of Sustainable Energy and Environment The Hong Kong University of Science and Technology(Guangzhou)Guangzhouthe People's Republic of China the hong kong university of science and technology interdisciplinary program office Hong Kong SARthe People's Republic of China Institute of Materials Research Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhenthe People's Republic of China School of science and Engineering Shenzhen Institute of Aggregate Science and TechnologyThe Chinese University of Hong KongShenzhenthe People's Republic of China HKUST Shenzhen-hong kong Collaborative Innovation Research Institute Shenzhenthe People's Republic of China Guangzhou HKUST Fok Ying Tung Research Institute Guangzhouthe People's Republic of China

Visible light-based human–machine interactive media is capable of transmitting electrical readouts to machines and providing intuitive feedback to users ***,many inorganic mechanoluminescent(ML)materials-based interactive media,typically ZnS-loaded phosphors(ZLPs),have been successfully ***,organic ML materials-based solutions were rarely exploited despite their huge merits of strong structural modification,abundant luminescence property,low cost,easy preparation,and so ***,we propose a novel interactive tactile display(ITD)based on organic ML materials(Cz-A6-dye)and triboelectric nanogenerator,with ultra-brightness(130%enhancement)and ultra-low threshold pressure(57%reduction)as compared to *** proposed ITD achieves the conversion of weak mechanical stimuli into visible light and electrical signals simultaneously,without extra power ***,the relationship between the luminous performance of organic ML materials and mechanical force is quantified,benefiting from the uniform ML layer *** by convolutional neural networks,the high-accuracy recognition(97.1%)for handwriting and identity of users is realized at the same ***,the ITD has great potential for intelligent wearable electronics and classified military applications.

关键词： interactive media organic mechanoluminescence triboelectric nanogenerators

Phase transformation behavior of a dual-phase nanostructured Fe-Ni-B-Si-P-Nb metallic glass and its correlation with stress-impedance properties

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Rare Metals 2023年第8期42卷 2757-2766页

作者： Jia-Cheng Ge Ai-Hua Liu Zhen-Duo Wu Yao Gu Yu-Bin Ke An-Ding Wang Yang Ren Song Tang Hui-Qiang Ying He Zhu Xun-Li Wang Si Lan Herbert Gleiter Institute of Nanoscience School of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing 210094China Department of Physics City University of Hong KongHong Kong999077China City university of hong kong(Dongguan) Dongguan 523000China Center for Neutron Scattering City University of Hong Kong Shenzhen Research InstituteShenzhen 518057China Spallation Neutron Source science Center Dongguan 523803China Guangdong-hong kong-Macao Joint Laboratory for Neutron Scattering science and technology Dongguan 523803China School of Materials science and Engineering Dongguan University of TechnologyDongguan 523808China

A study of the phase transformation process of a Fe-Ni-B-Si-P-Nb metallic glass using a suite of advanced characterization tools is *** electron microscopy(TEM)and small angle neutron scattering(SANS)experiments show that the as-spun metallic glass ribbon has a dual-phase structure with bcc nanoclusters of a size of 2-3 *** situ high-energy X-ray diffraction(XRD)reveals a three-stage crystallization process when heating the metallic glass into supercooled liquid *** isothermal annealing experiment shows the nanoclusters grow instantly without *** easy formation and phase stability of the nanoclusters are due to the low interfacial energy between the amorphous matrix and clusters,as real space analysis shows that the nanoclusters and the amorphous matrix share similar short-to-mediumrange *** further find that the dual-phase structure reduces local magneto-anisotropy and enhances effective magnetic permeability,resulting in an excellent stressimpedance effect without sacrificing *** work sheds light on the structure-property engineering of soft magnetic metallic glasses and provides a foundation for developing novel magnetic functional materials with nanostructured dual-phases.

关键词： Soft-magnetic property Metallic glass Phase transformation Synchrotron and neutron scattering Stressimpedance(SI)

Malaria transmission modelling: a network perspective

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Infectious Diseases of Poverty 2012年第1期1卷 99-106页

作者： Jiming Liu Bo Yang William K Cheung Guojing Yang Department of Computer science Hong Kong Baptist UniversityKowloon TongHong Kong College of Computer science and technology Jilin UniversityChangchunChina The Jockey Club School of Public Health and Primary Care Chinese University of Hong KongHong Kong

Malaria transmission can be affected by multiple or even hidden factors,making it difficult to timely and accurately predict the impact of elimination and eradication programs that have been undertaken and the potential resurgence and spread that may continue to *** approach at the moment is to develop and deploy surveillance systems in an attempt to identify them as timely as possible and thus to enable policy makers to modify and implement strategies for further preventing the *** of the surveillance data will be of temporal and spatial *** an interdisciplinary point of view,it would be interesting to ask the following important as well as challenging question:Based on the available surveillance data in temporal and spatial forms,how can we build a more effective surveillance mechanism for monitoring and early detecting the relative prevalence and transmission patterns of malaria?What we can note from the existing clustering-based surveillance software systems is that they do not infer the underlying transmission networks of ***,such networks can be quite informative and insightful as they characterize how malaria transmits from one place to *** can also in turn allow public health policy makers and researchers to uncover the hidden and interacting factors such as environment,genetics and ecology and to discover/predict malaria transmission patterns/*** network perspective further extends the present approaches to modelling malaria transmission based on a set of chosen *** this article,we survey the related work on transmission network inference,discuss how such an approach can be utilized in developing an effective computational means for inferring malaria transmission networks based on partial surveillance data,and what methodological steps and issues may be involved in its formulation and validation.

关键词： Malaria network policy

Thermal stability and deformation mechanisms in Ni-Co-Fe-Cr-Al-Ti-Nb-type nanoparticle-strengthened high-entropy alloys

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Journal of Materials science & technology 2023年第36期167卷 171-183页

作者： J.X.Hou J.Y.Zhang J.X.Zhang J.H.Luan Y.X.Wang B.X.Cao Y.L.Zhao Z.B.Jiao X.J.Liu W.W.Song P.K.Liaw T.Yang Department of Materials science and Engineering Hong Kong Institute for Advanced StudyCity University of Hong KongHong KongChina School of Materials science and Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China Department of Mechanical Engineering The Hong Kong Polytechnic UniversityHong KongChina Steel Institute RWTH Aachen UniversityAachen 52072Germany Institute of Materials Engineering University of KasselKassel 334125Germany Department of Materials science and Engineering The University of TennesseeKnoxvilleTN 37996-2200USA City university of hong kong China

The precipitate morphologies,coarsening kinetics,elemental partitioning behaviors,grain structures,and tensile properties were explored in detail for L1_(2)-strengthened Ni_(39.9)Co_(20)Fe_(15)Cr_(15)Al_(6)Ti_(4-x)Nb_(x)B_(0.1)(x=0 at.%,2 at.%,and 4 at.%)high-entropy alloys(HEAs).By substituting Ti with Nb,the spheroidal-to-cuboidal precipitate morphological transition,increase in the coarsening kinetics,and phase decomposition upon aging at 800°C *** excessive addition of Nb brings about the grain boundary precipitation of an Nb-rich phase along with the phase decomposition from the L1_(2)to lamellar-structured D019 phase upon the long-term aging *** partially substituting Ti with Nb,the chemically complex and thermally stable L12 phase with a composition of(Ni_(58.8)Co_(9.8)Fe_(2.7))(Al_(12.7)Ti_(5.8)Nb_(7.5)Cr_(2.3))ensures the stable phase structure and clean grain boundaries,which guarantees the superb high-temperature mechanical properties(791±7 MPa for yielding and 1013±11 MPa for failure)at 700℃.Stacking faults(SFs)were observed to prevail during the plastic deformation,offering a high work-hardening capability at 700°*** anomalous rise in the yield strength at 800℃was found,which could be ascribed to the multi-layered super-partial dislocations with a cross-slip configuration within the L1_(2)particles.

关键词： High-entropy alloys Coarsening kinetics Coherent precipitation strengthening Mechanical properties