| 1. |
- Abdel-Hafiez, Mahmoud, et al.
(författare)
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From Insulator to Superconductor : A Series of Pressure-Driven Transitions in Quasi-One-Dimensional TiS3 Nanoribbons
- 2024
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 24:18, s. 5562-5569
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Tidskriftsartikel (refereegranskat)abstract
- Transition metal trichalcogenides (TMTCs) offer remarkable opportunities for tuning electronic states through modifications in chemical composition, temperature, and pressure. Despite considerable interest in TMTCs, there remain significant knowledge gaps concerning the evolution of their electronic properties under compression. In this study, we employ experimental and theoretical approaches to comprehensively explore the high-pressure behavior of the electronic properties of TiS3, a quasi-one-dimensional (Q1D) semiconductor, across various temperature ranges. Through high-pressure electrical resistance and magnetic measurements at elevated pressures, we uncover a distinctive sequence of phase transitions within TiS3, encompassing a transformation from an insulating state at ambient pressure to the emergence of an incipient superconducting state above 70 GPa. Our findings provide compelling evidence that superconductivity at low temperatures of ∼2.9 K is a fundamental characteristic of TiS3, shedding new light on the intriguing high-pressure electronic properties of TiS3 and underscoring the broader implications of our discoveries for TMTCs in general.
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| 2. |
- Feng, Kui, et al.
(författare)
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Fused Bithiophene Imide Dimer-Based n-Type Polymers for High-Performance Organic Electrochemical Transistors
- 2021
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Ingår i: Angewandte Chemie International Edition. - : WILEY-V C H VERLAG GMBH. - 1433-7851 .- 1521-3773. ; 60:45, s. 24198-24205
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Tidskriftsartikel (refereegranskat)abstract
- The development of n-type organic electrochemical transistors (OECTs) lags far behind their p-type counterparts. In order to address this dilemma, we report here two new fused bithiophene imide dimer (f-BTI2)-based n-type polymers with a branched methyl end-capped glycol side chain, which exhibit good solubility, low-lying LUMO energy levels, favorable polymer chain orientation, and efficient ion transport property, thus yielding a remarkable OECT electron mobility (mu(e)) of up to approximate to 10(-2) cm(2) V-1 s(-1) and volumetric capacitance (C*) as high as 443 F cm(-3), simultaneously. As a result, the f-BTI2TEG-FT-based OECTs deliver a record-high maximum geometry-normalized transconductance of 4.60 S cm(-1) and a maximum mu C* product of 15.2 F cm(-1) V-1 s(-1). The mu C* figure of merit is more than one order of magnitude higher than that of the state-of-the-art n-type OECTs. The emergence of f-BTI2TEG-FT brings a new paradigm for developing high-performance n-type polymers for low-power OECT applications.
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| 3. |
- Li, Jiajia, 1995-, et al.
(författare)
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Impact of Fluorine‐Based Lithium Salts on SEI for All‐Solid‐State PEO‐Based Lithium Metal Batteries
- 2023
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Ingår i: Advanced Functional Materials. - : John Wiley & Sons. - 1616-301X .- 1616-3028. ; 33:38
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Tidskriftsartikel (refereegranskat)abstract
- LiF-rich solid-electrolyte-interphase (SEI) can suppress the formation of lithium dendrites and promote the reversible operation of lithium metal batteries. Regulating the composition of naturally formed SEI is an effective strategy, while understanding the impact and role of fluorine (F)-based Li-salts on the SEI characteristics is unavailable. Herein, LiFSI, LiTFSI, and LiPFSI are selected to prepare solid polymer electrolytes (SPEs) with poly(ethylene oxide) and polyimide, investigating the effects of molecular size, F contents and chemical structures (F-connecting bonds) of Li-salts and revealing the formation of LiF in the SEI. It is shown that the F-connecting bond is more significant than the molecular size and F element contents, and thus the performances of cells using LiPFSI are slightly better than LiTFSI and much better than LiFSI. The SPE containing LiPFSI can generate a high amount of LiF, and SPEs containing LiPFSI and LiTFSI can generate Li3N, while there is no Li3N production in the SEI for the SPE containing LiFSI. The preferential breakage bonds in LiPFSI are related to its position to Li anode, where Li-metal as the anode is important in forming LiF, and consequently the LiPFSI reduction mechanism is proposed. This study will boost other energy storage systems beyond Li-ion chemistries.
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| 4. |
- Li, Junwei, et al.
(författare)
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Is boar sperm freezability more intrinsically linked to spermatozoa than to the surrounding seminal plasma?
- 2018
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Ingår i: Animal Reproduction Science. - : ELSEVIER SCIENCE BV. - 0378-4320 .- 1873-2232. ; 195, s. 30-37
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Tidskriftsartikel (refereegranskat)abstract
- This study aimed to elucidate the effect of seminal plasma (SP) from post-SRF on boar sperm freezability and, in addition, to determine the relevance of sperm itself to sustain cryopreservation, regardless of the SP surrounding them. Twelve ejaculates from three boars were manually collected in fractions/portions, P1: the first 10 mL of the SRF, P2: the rest of the SRF and the post-SRF. Immediately, samples were centrifuged to separate spermatozoa from the surrounding SP. Spermatozoa from P1 and P2 were then incubated with its own SP or that from post-SRF, diluted in BTS (1:1, v/v) at 17 degrees C overnight before being frozen in 0.5 mL straws using a standard protocol. Sperm motility (total and progressive) deteriorated (P amp;lt; 0.05) when P1- or P2-sperm when incubated overnight in SP from post-SRF, while sperm viability differed between P1 and P2 (P amp;lt; 0.05) regardless of the SP they were incubated in. Post-thaw sperm quality and functionality differed between P1 and P2, regardless of the SP used for overnight pre-freezing incubation. Post-thaw motility (P amp;lt; 0.05) and viability (P amp;lt; 0.01), as well as plasma membrane fluidity (P amp;lt; 0.05) or lipid peroxidation values (P amp;lt; 0.01) were best in P1 sperm compared to those of P2. The protein profile of sperm from P1 and P2, analyzed by 2D-PAGE, showed qualitative differences, which suggest that sperm rather than SP would explain differences in sperm freezability between ejaculate fractions/portions. Use of P1 fraction spermatozoa seems thus optimal for cryopreservation.
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| 5. |
- Li, Junwei, et al.
(författare)
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Post-thaw boar sperm motility is affected by prolonged storage of sperm in liquid nitrogen. A retrospective study
- 2018
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Ingår i: Cryobiology. - : Elsevier. - 0011-2240 .- 1090-2392. ; 80, s. 119-125
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Tidskriftsartikel (refereegranskat)abstract
- Owing to the quick genetic turnover of the pig industry, most AT-boar sires live 2-3 yr, a period during which for 1-2 yr their semen is extended and used in liquid form for AI. Despite showing low cryosurvival, affecting fertility after AI, boar semen is frozen for easiness of transport overseas and reposition of valuable genetics. For the latter, semen is stored in liquid nitrogen (LN2, cryostorage) for many years, a controversial practice. Here we studied how length of cryostorage could affect sperm quality. Straws (0.5 mL) frozen using the same cryopreservation protocol at one specific location from AI-sires of proven fertility were stored in LN2 for up to 8 yr. Post thaw sperm quality was evaluated after 2, 4 or 8 yr of cryostorage, always compared to early thawing (15 d after freezing). Sperm motility and kinematics were evaluated post-thaw using CASA and sperm viability was cytometrically evaluated using specific fluorophores. Sperm viability was not affected by length of cryostorage, but total and progressive sperm motility were lower (p amp;lt; 0.01) in sperm samples cryostored for 4 or 8 yr compared to those thawed 15 d after freezing. Cryostorage time affected sperm kinetics, but with greater intensity in the samples cryostored for 4 yr (p amp;lt; 0.001) than in those for 2 yr (p amp;lt; 0.01). The fact that the major phenotypic characteristic of boar spermatozoa, motility, is constrained by time of cryostorage should be considered when building cryobanks of pig semen. Attention should be placed on the finding that amp;gt; 2 yr of cryostorage time can be particularly detrimental for the post-thaw motility of some sires, which might require increasing sperm numbers for AI.
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| 6. |
- Li, Jiahui, et al.
(författare)
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Pseudocapacitive Heteroatom-Doped Carbon Cathode for Aluminum-Ion Batteries with Ultrahigh Reversible Stability
- 2024
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Ingår i: Energy & Environmental Materials. - : WILEY. - 2575-0356.
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Tidskriftsartikel (refereegranskat)abstract
- Aluminum (Al)-ion batteries have emerged as a potential alternative to conventional ion batteries that rely on less abundant and costly materials like lithium. Nonetheless, given the nascent stage of advancement in Al-ion batteries (AIBs), attaining electrode materials that can leverage both intercalation capacity and structural stability remains challenging. Herein, we demonstrate a C3N4-derived layered N,S heteroatom-doped carbon, obtained at different pyrolysis temperatures, as a cathode material for AIBs, encompassing the diffusion-controlled intercalation and surface-induced capacity with ultrahigh reversibility. The developed layered N,S-doped corbon (N,S-C) cathode, synthesized at 900 degrees C, delivers a specific capacity of 330 mAh g(-1) with a relatively high coulombic efficiency of similar to 85% after 500 cycles under a current density of 0.5 A g(-1). Owing to its reinforced adsorption capability and enlarged interlayer spacing by doping N and S heteroatoms, the N,S-C900 cathode demonstrates outstanding energy storage capacity with excellent rate performance (61 mAh g(-1) at 20 A g(-1)) and ultrahigh reversibility (90 mAh g(-1) at 5 A g(-1) after 10 000 cycles).
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| 7. |
- Li, Junwei, et al.
(författare)
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Seminal plasma antioxidants are directly involved in boar sperm cryotolerance
- 2018
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Ingår i: Theriogenology. - : ELSEVIER SCIENCE INC. - 0093-691X .- 1879-3231. ; 107, s. 27-35
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Tidskriftsartikel (refereegranskat)abstract
- Boar ejaculates are ejected in fractions with a specific composition in terms of sperm numbers and seminal plasma (SP), which is reflected in the varying sperm cryotolerance observed among different fractions. As boar sperm are particularly sensitive to oxidative stress, this study evaluated the role of SP antioxidants in the observed differences in sperm cryotolerance among ejaculate fractions. Ten ejaculates from five boars were manually collected in fractions: the first 10 mL of the sperm-rich fraction (SRF), the rest of the SRF and the post-SRF. Semen samples comprising the entire ejaculate (EE) were created by proportionally mixing the three fractions described above. Each of the 40 resulting semen samples was split into two aliquots: one was used for sperm cryopreservation following a standard protocol utilizing 0.5-mL straws, and the other was used to collect SP for antioxidant assessment. Frozen-thawed (FT) sperm from the SRF (the first 10 mL of the SRF and the rest of the SRF) and those from post-SRF were of the highest and worst quality, respectively, which was measured in terms of total and objective progressive motility and viability (P amp;lt; 0.01). Viable FT sperm from the post-SRF generated more reactive oxygen species and experienced more lipid peroxidation than those from the SRF (both the first 10 mL and the rest of the SRF) (P amp;lt; 0.01). The percentage of FT sperm exhibiting fragmented nuclear DNA did not differ among ejaculate fractions and the EE. Catalase, glutathione peroxidase and glutathione peroxidase 5 (GPx-5) were lowest in SP from the first 10 mL of the SRF (P amp;lt; 0.001), whereas superoxide dismutase (SOD) and paraoxonase 1 (PON-1) were highest in SP of the SRF (both the first 10 mL and the rest of the SRF) (P amp;lt; 0.01). Trolox-equivalent antioxidant capacity (TEAC) and the ferric-reducing ability of plasma (FRAP) were highest in SP from the first 10 mL of the SRF and lowest in the post-SRF (P amp;lt; 0.001), whereas cupric-reducing antioxidant capacity was lowest (P amp;lt; 0.05) in SP from the first 10 mL of the SRF. Regression analyses indicated that certain SP antioxidants had good predictive value for post-thaw recovery rates of total motility (R-2 = 54.8%, P amp;lt; 0.001; including SOD, TEAC and FRAP) and viability (R-2 = 56.1%, P amp;lt; 0.001; including SOD, PON-1, GPx-5 and TEAC). These results demonstrated that certain SP antioxidants are positively involved in boar sperm cryotolerance, minimizing the oxidative stress imposed by cryogenic handling. (C) 2017 Elsevier Inc. All rights reserved.
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| 8. |
- Li, Long, et al.
(författare)
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Discriminative Co-Saliency and Background Mining Transformer for Co-Salient Object Detection
- 2023
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Ingår i: 2023 IEEE/CVF CONFERENCE ON COMPUTER VISION AND PATTERN RECOGNITION, CVPR. - : IEEE COMPUTER SOC. - 9798350301298 - 9798350301304 ; , s. 7247-7256
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Konferensbidrag (refereegranskat)abstract
- Most previous co-salient object detection works mainly focus on extracting co-salient cues via mining the consistency relations across images while ignore explicit exploration of background regions. In this paper, we propose a Discriminative co-saliency and background Mining Transformer framework (DMT) based on several economical multi-grained correlation modules to explicitly mine both co-saliency and background information and effectively model their discrimination. Specifically, we first propose a region-to-region correlation module for introducing inter-image relations to pixel-wise segmentation features while maintaining computational efficiency. Then, we use two types of pre-defined tokens to mine co-saliency and background information via our proposed contrast-induced pixel-to-token correlation and co-saliency token-to-token correlation modules. We also design a token-guided feature refinement module to enhance the discriminability of the segmentation features under the guidance of the learned tokens. We perform iterative mutual promotion for the segmentation feature extraction and token construction. Experimental results on three benchmark datasets demonstrate the effectiveness of our proposed method. The source code is available at: https://github.com/dragonlee258079/DMT.
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| 9. |
- Li, Long, et al.
(författare)
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Robust Perception and Precise Segmentation for Scribble-Supervised RGB-D Saliency Detection
- 2024
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Ingår i: IEEE Transactions on Pattern Analysis and Machine Intelligence. - : IEEE COMPUTER SOC. - 0162-8828 .- 1939-3539. ; 46:1, s. 479-496
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Tidskriftsartikel (refereegranskat)abstract
- This paper proposes a scribble-based weakly supervised RGB-D salient object detection (SOD) method to relieve the annotation burden from pixel-wise annotations. In view of the ensuing performance drop, we summarize two natural deficiencies of the scribbles and try to alleviate them, which are the weak richness of the pixel training samples (WRPS) and the poor structural integrity of the salient objects (PSIO). WRPS hinders robust saliency perception learning, which can be alleviated via model design for robust feature learning and pseudo labels generation for training sample enrichment. Specifically, we first design a dynamic searching process module as a meta operation to conduct multi-scale and multi-modal feature fusion for the robust RGB-D SOD model construction. Then, a dual-branch consistency learning mechanism is proposed to generate enough pixel training samples for robust saliency perception learning. PSIO makes direct structural learning infeasible since scribbles can not provide integral structural supervision. Thus, we propose an edge-region structure-refinement loss to recover the structural information and make precise segmentation. We deploy all components and conduct ablation studies on two baselines to validate their effectiveness and generalizability. Experimental results on eight datasets show that our method outperforms other scribble-based SOD models and achieves comparable performance with fully supervised state-of-the-art methods.
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| 10. |
- Li, Zeya, et al.
(författare)
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Robustness of Trion State in Gated Monolayer MoSe2 under Pressure
- 2023
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 23:22, s. 10282-10289
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Tidskriftsartikel (refereegranskat)abstract
- Quasiparticles consisting of correlated electron(s) and hole(s), such as excitons and trions, play important roles in the optical phenomena of van der Waals semiconductors and serve as unique platforms for studies of many-body physics. Herein, we report a gate-tunable exciton-to-trion transition in pressurized monolayer MoSe2, in which the electronic band structures are modulated continuously within a diamond anvil cell. The emission energies of both the exciton and trion undergo large blueshifts over 90 meV with increasing pressure. Surprisingly, the trion binding energy remains constant at 30 meV, regardless of the applied pressure. Combining ab initio density functional theory calculations and quantum Monte Carlo simulations, we find that the remarkable robustness of the trion binding energy originates from the spatially diffused nature of the trion wave function and the weak correlation between its constituent electron-hole pairs. Our findings shed light on the optical properties of correlated excitonic quasiparticles in low-dimensional materials.
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