排序方式： 共有25条查询结果，搜索用时 15 毫秒
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Tahmida N. Huq Lana C. Lee Lissa Eyre Weiwei Li Robert A. Jagt Chaewon Kim Sarah Fearn Vincenzo Pecunia Felix Deschler Judith L. MacManus‐Driscoll Robert L. Z. Hoye 《Advanced functional materials》2020,30(13)
In the search for nontoxic alternatives to lead‐halide perovskites, bismuth oxyiodide (BiOI) has emerged as a promising contender. BiOI is air‐stable for over three months, demonstrates promising early‐stage photovoltaic performance and, importantly, is predicted from calculations to tolerate vacancy and antisite defects. Here, whether BiOI tolerates point defects is experimentally investigated. BiOI thin films are annealed at a low temperature of 100 °C under vacuum (25 Pa absolute pressure). There is a relative reduction in the surface atomic fraction of iodine by over 40%, reduction in the surface bismuth fraction by over 5%, and an increase in the surface oxygen fraction by over 45%. Unexpectedly, the Bi 4f7/2 core level position, Fermi level position, and valence band density of states of BiOI are not significantly changed. Further, the charge‐carrier lifetime, photoluminescence intensity, and the performance of the vacuum‐annealed BiOI films in solar cells remain unchanged. The results show BiOI to be electronically and optoelectronically robust to percent‐level changes in surface composition. However, from photoinduced current transient spectroscopy measurements, it is found that the as‐grown BiOI films have deep traps located ≈0.3 and 0.6 eV from the band edge. These traps limit the charge‐carrier lifetimes of BiOI, and future improvements in the performance of BiOI photovoltaics will need to focus on identifying their origin. Nevertheless, these deep traps are three to four orders of magnitude less concentrated than the surface point defects induced through vacuum annealing. The charge‐carrier lifetimes of the BiOI films are also orders of magnitude longer than if these surface defects were recombination active. This work therefore shows BiOI to be robust against processing conditions that lead to percent‐level iodine‐, bismuth‐, and oxygen‐related surface defects. This will simplify and reduce the cost of fabricating BiOI‐based electronic devices, and stands in contrast to the defect‐sensitivity of traditional covalent semiconductors. 相似文献
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Tom James Embleton Jeongsik Yun Jae-Hong Choi Jongho Kim Sumyeong Choi Chaewon Lee Yoonkook Son Pilgun Oh 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(25):2206576
The mainstream of high-energy cathode development is focused on increasing the Ni-ratio in layered structured cathode materials. The increment of the Ni portion in the layered cathode material escalates not only the deliverable capacity but also the structural degradation. High-Ni layered cathodes are highly vulnerable to exposure to air that contains CO2 and H2O, forming problematic residual lithium compounds at the surface. In this work, a novel air- and moisture robust surface modification is reported for LiNi0.8Co0.1Mn0.1O2 (NCM811) via the sol-gel coating method that selectively coats the internal surface area of the polycrystalline morphology secondary particles. Bare-, Li2SnO3-coated and LiCoO2-coated NCM811 are exposed to different ambient environments (air, hot-air, and moisture-air) to systematically investigate the correlation between the internal/external coating morphology and performance degradations. The LiCoO2-coated NCM811s exhibit high-capacity retention after exposure to all environments, due to the internal surface coating that prevents the penetration of harmful compounds into the polycrystalline NCM811. On the other hand, the Li2SnO3-coated NCM811s exposed to the ambient environments show gradual capacity fading, implying the occurrence of internal degradation. This paper highlights the impact of the internal degradation of polycrystalline NCM811 after environmental exposure and the correct coating mechanisms required to successfully prevent it. 相似文献
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布谷鸟过滤器是一种高效的概率型数据结构, 该数据结构可以快速判断某个元素是否存在于给定集合中, 被广泛应用于计算机网络、物联网应用以及数据库系统中. 在实践中, 上述系统通常需要处理海量数据以及大量并发请求. 实现支持高并发的布谷鸟过滤器可以显著提升系统吞吐以及数据处理能力, 对提升系统性能至关重要. 为此, 设计一个支持无锁并发的布谷鸟过滤器. 该过滤器通过所提出的两阶段查询、路径探查与元素迁移分离, 以及基于多机器字比较并交换的原子迁移技术实现高性能的查询、插入和删除操作. 理论分析和实验验证结果均表明, 无锁并发布谷鸟过滤器显著提升现有最先进算法的并发性能. 无锁并发布谷鸟过滤器的查询吞吐量, 平均为使用细粒度锁的布谷鸟过滤器的查询吞吐量的1.94倍. 相似文献
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Chaewon Park Eunjung Kim Geunseon Park Byoung Choul Kim Srivithya Vellampatti Jong-Woo Lim Sojeong Lee Soohyun Chung Sung-Hoon Jun Sangyoon Lee Sajid Ali Minjoo Yeom Daesub Song Seungjoo Haam 《Advanced functional materials》2023,33(31):2214603
The emergence of fatal viruses that pose continuous threats to global health has fueled the intense effort to develop direct, accurate, and high-throughput virus detection platforms. Current diagnostic methods, including qPCR and rapid antigen tests, indicate how much of the virus is present, whether small fragments or whole viruses. However, these methods do not indicate the probability of the virus to be active, capable of interacting with host cells and initiating the infection cycle. Herein, a sialic acid-presenting fusogenic liposome (sLipo–Chol) nanosensor with purposefully modulated membrane rigidity to rapidly detect the fusion-competent influenza A virus (IAV) is developed. This nanosensor possesses virus-specific features, including hemagglutinin (HA) binding and HA-mediated membrane fusion. It is explored how the fusogenic capability of sLipo–Chol with different membrane rigidities impacts their sensing performance by integrating Förster resonance energy transfer (FRET) pairs into the bilayers. The addition of an intact virus led to instant FRET signal changes, thus enabling the direct detection of diverse IAV subtypes—even in avian fecal samples—within an hour at room temperature. Therefore, the sensing approach, with an understanding of the cellular pathogenesis of influenza viruses, will aid in developing bioinspired nanomaterials for evolution into nanosystems to detect infection-competent viruses. 相似文献
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Point‐of‐Care Diagnostics: Host Cell Mimic Polymersomes for Rapid Detection of Highly Pathogenic Influenza Virus via a Viral Fusion and Cell Entry Mechanism (Adv. Funct. Mater. 34/2018) 
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Geunseon Park Hyun-Ouk Kim Jong-Woo Lim Chaewon Park Minjoo Yeom Daesub Song Seungjoo Haam 《Nano Research》2022,(3):2254-2262
A recurrent pandemic with unpredictable viral nature has implied the need for a rapid diagnostic technology to facilitate timely and appropriate countermeasures... 相似文献
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Hyo Lee Sojeong Lee Chaewon Park Minjoo Yeom Jong-Woo Lim Thi Thu Hang Vu Eunjung Kim Daesub Song Seungjoo Haam 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(26):2207117
African swine fever virus (ASFV) is a severe and persistent threat to the global swine industry. As there are no vaccines against ASFV, there is an immense need to develop easy-to-use, cost-effective, and rapid point-of-care (POC) diagnostic platforms to detect and prevent ASFV outbreaks. Here, a novel POC diagnostic system based on affinity column chromatography for the optical detection of ASFV is presented. This system employs an on-particle hairpin chain reaction to sensitize magnetic nanoclusters with long DNA strands in a target-selective manner, which is subsequently fed into a column chromatography device to produce quantitatively readable and colorimetric signals. The detection approach does not require expensive analytical apparatus or immobile instrumentation. The system can detect five genes constituting the ASFV whole genome with a detection limit of ≈19.8 pm in swine serum within 30 min at laboratory room temperature. With an additional pre-amplification step using polymerase chain reaction (PCR), the assay is successfully applied to detect the presence of ASFV in 30 suspected swine samples with 100% sensitivity and specificity, similar to quantitative PCR. Thus, this simple, inexpensive, portable, robust, and customizable platform for the early detection of ASFV can facilitate the timely surveillance and implementation of control measures. 相似文献
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Woonsung Na Minjoo Yeom Jihye Choi Jihye Kim Jong‐Woo Lim Dayeon Yun Haejin Chun Geunseon Park Chaewon Park Jeong‐Ki Kim Dae Gwin Jeong Van Phan Le Kwangyeol Lee Jae Myun Lee Hyoung Hwa Jeong Daesub Song Seungjoo Haam 《Advanced functional materials》2018,28(34)
Highly pathogenic avian influenza virus (HPAIV) infections have occurred continuously and crossed the species barrier to humans, leading to fatalities. A polymerase chain reaction based molecular test is currently the most sensitive diagnostic tool for HPAIV; however, the results must be analyzed in centralized diagnosis systems by a trained individual. This requirement leads to delays in quarantine and isolation. To control the spread of HPAIV, rapid and accurate diagnostics suitable for field testing are needed, and the tests must facilitate a differential diagnosis between HPAIV and low pathogenic avian influenza virus (LPAIV), which undergo cleavage specifically by trypsin‐ or furin‐like proteases, respectively. In this study, a differential avian influenza virus rapid test kit is developed and evaluated in vitro and using clinical specimens from HPAIV H5N1‐infected animals. It is demonstrated that this rapid test kit provides highly sensitive and specific detection of HPAIV and LPAIV and is thus a useful field diagnostic tool for H5N1 HPAIV outbreaks and for rapid quarantine control of the disease. 相似文献
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Emergence of novel two-dimensional (2-D) templates, e.g., graphene oxide, has signified new intriguing opportunities to couple nanocrystals electronically to the microscopic 2-D contacts. A promising approach to uniform dispersion of inorganic nanocrystals on the 2-D interfaces is to graft them through chemical bonding. The 2-D dispersion would offer a unique opportunity to address one of the primary challenges in the field of nanotechnology: fulfilling excellent chemical and physical properties of the nanocrystals in electronic solid-state devices. In this study, we blended colloidal nanocrystals with graphene oxide in aqueous solution in attempts to bind the nanocrystals on reactive sites of the graphene oxide surface, thereby achieving uniform loading. Interestingly, the nanocrystals undergo significant crystalline transformation even under relatively moderate reaction conditions. The growth of particle size and the drastic crystalline deformation, e.g., from wurtzite CdSe to amorphous Se, appear to take place in the proximity of acidic functional groups on graphene oxide. Photocarriers also play a key role in the reaction: under room light, the transformation yielded dramatic size increase and crystalline transformation, whereas in the dark, the change was suppressed. The experimental results presented in this study provide guidelines for uniform 2-D loading of colloidal nanocrystals on graphene oxide. The findings suggest that the surface acidity be titrated for colloidal nanocrystals to deposit on the graphitic layer and to avoid unwanted changes of nanocrystal size and properties. 相似文献