| 1. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Yu, Xianbin, et al.
(författare)
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Photonic-wireless Communication and Sensing in the Terahertz Band
- 2023
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Ingår i: 2023 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION, OFC. - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- This paper reviews the potential of THz photonics in communication and sensing by presenting our experimental results in the 300-500 GHz. Benefiting from the large available bandwidth in both THz and photonics, THz communications with high speed and THz imaging with high resolution have been achieved.
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| 3. |
- Zhang, Hongqi, et al.
(författare)
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Tbit/s Multi-Dimensional Multiplexing THz-Over-Fiber for 6G Wireless Communication
- 2021
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Ingår i: Journal of Lightwave Technology. - : Institute of Electrical and Electronics Engineers (IEEE). - 0733-8724 .- 1558-2213. ; 39:18, s. 5783-5790
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Tidskriftsartikel (refereegranskat)abstract
- Photonics-aided terahertz (THz) wireless systems have been progressively developed to accommodate the forthcoming wireless communication with extremely high data rates in recent years. However, restrained by the obtainable signal-to-noise ratio (SNR) and the dimensions explored in THz photonic wireless systems, achieving data rates of Tbit/s and beyond is still challenging. In this paper, we present a multi-dimensional multiplexing Tbit/s THz-over-Fiber wireless communication system, by efficiently benefiting from the multiplexing gain in both optical wavelength and space domains. Enabled by a combined routine of an optical frequency comb, a low inter-core crosstalk (IC-XT) multi-core fiber and advanced digital signal processing, a line rate of up to 1176 Gbit/s over a wireless distance of 10 m in the 350 GHz band is experimentally demonstrated without any THz amplifiers, resulting in a net data rate of up to 1059 Gbit/s. To the best of our knowledge, this is the first time that beyond Tbit/s wireless data rate is successfully achieved in the THz region above 300 GHz, making a significant contribution to the development of THz-over-Fiber systems for the sixth generation (6G) wireless communication.
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| 4. |
- Wang, Siqi, et al.
(författare)
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Adjusting Competitive Reaction to Control Nucleation and Growth of MnO2 for a High-Stress Output Electrochemical Actuator
- 2023
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Ingår i: ACS APPLIED ELECTRONIC MATERIALS. - : AMER CHEMICAL SOC. - 2637-6113. ; 5:9, s. 4836-4845
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Tidskriftsartikel (refereegranskat)abstract
- Manganese dioxide (MnO2) with biocompatibility has promising applications in low-voltage electrochemical actuators of implantable medical devices, which can convert electrical energy to mechanical motion. However, the unsatisfactory actuation strain restricts the generation of a larger output stress of MnO2 for practical application. Herein, a competitive reaction-driven-MnO2 (CRD-MnO2) nanorod network was fabricated on a nickel (Ni) thin-film substrate by adjusting the component molar ratios. We find that the competitive reaction between 3,4-ethylene-dioxythiophene (EDOT) polymerization and oxidation of Mn2+ controls the nucleation and growth behavior of MnO2. The variation in the electron environment, newly generated oxygen vacancies, and a higher content of structural water effectively improve the electroactivity of MnO2 and simultaneously cause more serious Jahn-Teller (JT) distortion of the crystal octahedrons. Thus, an excellent output performance simultaneously having a much higher actuating strain of 8.3% and an actuation stress of 390.1 MPa is generated during a redox reaction between Mn4+ and Mn3+ under 0-1 V. Moreover, the CRD-MnO2/Ni composite actuating films assembled on a 3D-printed resin model of a human hand with separated finger joints can perform smooth grasping and releasing actions, demonstrating a huge potential for in vitro rehabilitation exercises and implantability for people with finger dyskinesia. This work provides a strategy for actuator material fabrication by controlling a nucleation and growth process by adjusting a competitive reaction.
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| 5. |
- Zhang, Siqi, et al.
(författare)
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Boosting the Efficiency of Dye-Sensitized Solar Cells by a Multifunctional Composite Photoanode to 14.13 %
- 2023
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Ingår i: Angewandte Chemie International Edition. - : John Wiley & Sons. - 1433-7851 .- 1521-3773. ; 62:23
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Tidskriftsartikel (refereegranskat)abstract
- We report a new strategy to fabricate a multifunctional composite photoanode containing TiO2 hollow spheres (TiO2-HSs), Au nanoparticles (AuNPs) and novel NaYF4 : Yb,Er@NaLuF4 : Eu@SiO2 upconversion nanoparticles (UCNPs). The AuNPs are grown on the photoanode film including TiO2-HSs and UCNPs by a simple in situ plasmonic treatment. As a result, an impressive power conversion efficiency of 14.13 % is obtained, which is a record for N719 dye-based dye-sensitized solar cells, demonstrating great potential for the solar cells toward commercialization. This obvious enhancement is ascribed to a collaborative mechanism of the TiO2-HSs exhibiting excellent light-scattering ability, of the UCNPs converting near-infrared photons into visible photons and of the AuNPs presenting outstanding surface plasmon resonance effect. Notably, a steady-state experiment further reveals that the champion cell exhibits 95.33 % retainment in efficiency even after 180 h of measurements, showing good device stability.
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| 6. |
- Zhang, Siqi, et al.
(författare)
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Multifunctional Composite Photoanode Containing a TiO2 Microarchitecture with Near-Infrared Upconversion Nanoparticles for Dye-Sensitized Solar Cells
- 2024
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Ingår i: ACS Applied Nano Materials. - : American Chemical Society (ACS). - 2574-0970. ; 7:7, s. 6851-6860
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Tidskriftsartikel (refereegranskat)abstract
- Incorporating functionalized TiO2 microarchitectures or upconversion nanoparticles (UCNPs) into photoanodes is deemed to be two effective ways to boost the photovoltaic performance of dye-sensitized solar cells (DSSCs). Nonetheless, studies combining functionalized TiO2 and UCNPs for the development of composite photoanode films in DSSCs still remain scarce. In view of this, we present a facile strategy for the design and preparation of a multifunctional composite photoanode containing P25 nanoparticles, peanut-like (PN) TiO2 microstructures, and NaYF4:Yb,Er@NaYF4:Nd@SiO2 core–shell–shell UCNPs. It is found that the DSSC containing a dual-functional photoanode using PN TiO2 as a light-scattering layer and P25 as a transparent layer can achieve a photovoltaic efficiency of 9.01%, presenting a 26.37% enhancement over the blank device. More importantly, the addition of UCNPs can further enhance the photoelectric performance of the DSSC device, realizing an optimal photovoltaic efficiency of 10.58%, one of the highest reported efficiencies for UCNP-based DSSCs with the common N719 photosensitizer. Such a remarkable improvement is mainly due to a synergetic effect of the UCNPs absorbing the near-infrared light and of the PN TiO2 presenting excellent light-scattering potency. Specifically, steady-state experiments reveal that the best-performing device shows only a small efficiency loss after 120 h of testing, exhibiting good device stability. The present work demonstrates the importance of composite photoanodes in enhancing the photovoltaic performances of solar cells.
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| 7. |
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| 8. |
- Chen, Jie, et al.
(författare)
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Bidirectional Mendelian Randomisation Analysis Provides Evidence for the Causal Involvement of Dysregulation of CXCL9, CCL11 and CASP8 in the Pathogenesis of Ulcerative Colitis
- 2023
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Ingår i: Journal of Crohn's & Colitis. - : Oxford University Press. - 1873-9946 .- 1876-4479. ; 17:5, s. 777-785
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Tidskriftsartikel (refereegranskat)abstract
- Background and Aims Systemic inflammation is well recognised to be associated with ulcerative colitis [UC], but whether these effects are causal or consequential remains unclear. We aimed to define potential causal relationship of cytokine dysregulation with different tiers of evidence. Methods We first synthesised serum proteomic profiling data from two multicentred observational studies, in which a panel of systemic inflammatory proteins was analysed to examine their associations with UC risk. To further dissect observed associations, we then performed a bidirectional two-sample Mendelian randomisation [TSMR] analysis from both forward and reverse directions using five genome-wide association study [GWAS] summary level data for serum proteomic profiles and the largest GWAS of 28 738 European-ancestry individuals for UC risk. Results Pooled analysis of serum proteomic data identified 14 proteins to be associated with the risk of UC. Forward MR analysis using only cis-acting protein quantitative trait loci [cis-pQTLs] or trans-pQTLs further validated causal associations of two chemokines and the increased risk of UC: C-X-C motif chemokine ligand 9 [CXCL9] [OR 1.45, 95% CI 1.08, 1.95, p = 0.012] and C-C motif chemokine ligand 11 [CCL11] [OR 1.14, 95% CI 1.09, 1.18, p = 3.89 x 10(-10)]. Using both cis- and trans-acting pQTLs, an association of caspase-8 [CASP8] [OR 1.04, 95% CI 1.03, 1.05, p = 7.63 x 10(-19)] was additionally identified. Reverse MR did not find any influence of genetic predisposition to UC on any of these three inflammation proteins. Conclusion Pre-existing elevated levels of CXCL9, CCL11 and CASP8 may play a role in the pathogenesis of UC.
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| 9. |
- Geng, Huifang, et al.
(författare)
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Controlled synthesis of highly stable lead-free bismuth halide perovskite nanocrystals : tructures and photophysics
- 2023
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Ingår i: SCIENCE CHINA Materials. - : Springer Science and Business Media LLC. - 2095-8226 .- 2199-4501. ; 66:5, s. 2079-2089
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Tidskriftsartikel (refereegranskat)abstract
- Recently, cesium bismuth halide perovskites have emerged as potential substitutes to their counterparts, cesium lead halide perovskites, owing to their low toxicity. However, the photophysics of cesium-bismuth halides nanocrystals (NCs) have not yet been fully rationalized because their structures remain highly debated. The ultraviolet-visible (UV-vis) absorption along with other photophysical properties such as the nature and lifetime of the excited states vary considerably across the previous reports. Here, we successfully synthesize pure Cs3BiBr6 and Cs3Bi2Br9 NCs via a modified hot-injection method, where the structure can be easily controlled by tuning the reaction temperature. The UV-vis absorption spectrum of the pure Cs3Bi2Br9 NCs features two characteristic peaks originating from the absorption of the first exciton and second exciton, respectively, which ultimately clarifies the debate in the previous reports. Using femtosecond transient absorption spectroscopy, we systematically investigate the excited state dynamics of the Cs3Bi2Br9 NCs and reveal that the photoexcited carriers undergo a self-trapping process within 3 ps after excitation. More intriguingly, the Cs3Bi2Br9 NCs prepared by this method show much better photostability than those prepared by the ligand-assisted reprecipitation process. Photodetectors based on these Cs3Bi2Br9 NCs show a sensitive light response, demonstrating the definite potential for breakthrough optoelectronic applications. [Figure not available: see fulltext.].
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| 10. |
- Lei, Jian, et al.
(författare)
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Abnormal expression of chondroitin sulfate sulfotransferases in the articular cartilage of pediatric patients with Kashin-Beck disease
- 2020
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Ingår i: Histochemistry and Cell Biology. - : Springer Science and Business Media LLC. - 0948-6143 .- 1432-119X. ; 153:3, s. 153-164
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study is to investigate the expression of enzymes involved in the sulfation of articular cartilage from proximal metacarpophalangeal (PMC) joint cartilage and distal metacarpophalangeal (DMC) joint cartilage in children with Kashin-Beck disease (KBD). The finger cartilage samples of PMC and DMC were collected from KBD and normal children aged 5-14 years old. Hematoxylin and eosin staining as well as immunohistochemical staining were used to observe the morphology and quantitate the expression of carbohydrate sulfotransferase 3 (CHST-3), carbohydrate sulfotransferase 12 (CHST-12), carbohydrate sulfotransferase 13 (CHST-13), uronyl 2-O-sulfotransferase (UST), and aggrecan. In the results, the numbers of chondrocyte decreased in all three zones of PMC and DMC in the KBD group. Less positive staining cells for CHST-3, CHST-12, CHST-13, UST, and aggrecan were observed in almost all three zones of PMC and DMC in KBD. The positive staining cell rates of CHST-12 were higher in superficial and middle zones of PMC and DMC in KBD, and a significantly higher rate of CHST-13 was observed only in superficial zone of PMC in KBD. In conclusion, the abnormal expression of chondroitin sulfate sulfotransferases in chondrocytes of KBD children may provide an explanation for the cartilage damage, and provide therapeutic targets for the treatment.
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| 11. |
- Li, Xin, et al.
(författare)
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Halide Double Perovskite Nanocrystals Doped with Rare-Earth Ions for Multifunctional Applications
- 2023
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Ingår i: Advanced Science. - 2198-3844. ; 10:20
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Tidskriftsartikel (refereegranskat)abstract
- Most lead-free halide double perovskite materials display low photoluminescence quantum yield (PLQY) due to the indirect bandgap or forbidden transition. Doping is an effective strategy to tailor the optical properties of materials. Herein, efficient blue-emitting Sb3+-doped Cs2NaInCl6 nanocrystals (NCs) are selected as host, rare-earth (RE) ions (Sm3+, Eu3+, Tb3+, and Dy3+) are incorporated into the host, and excellent PLQY of 80.1% is obtained. Femtosecond transient absorption measurement found that RE ions not only served as the activator ions but also filled the deep vacancy defects. Anti-counterfeiting, optical thermometry, and white-light-emitting diodes (WLEDs) are exhibited using these RE ions-doped halide double perovskite NCs. For the optical thermometry based on Sm3+-doped Cs2NaInCl6:Sb3+ NCs, the maximum relative sensitivity is 0.753% K−1, which is higher than those of most temperature-sensing materials. Moreover, the WLED fabricated by Sm3+-doped Cs2NaInCl6:Sb3+ NCs@PMMA displays CIE color coordinates of (0.30, 0.28), a luminous efficiency of 37.5 lm W−1, a CCT of 8035 K, and a CRI over 80, which indicate that Sm3+-doped Cs2NaInCl6:Sb3+ NCs are promising single-component white-light-emitting phosphors for next-generation lighting and display technologies.
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| 12. |
- Liu, Juan, 1994, et al.
(författare)
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Restricting Promiscuity of Plant Flavonoid 3'-Hydroxylase and 4'-O-Methyltransferase Improves the Biosynthesis of (2S)-Hesperetin in E. coli
- 2023
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Ingår i: Journal of Agricultural and Food Chemistry. - 0021-8561 .- 1520-5118. ; 71:25, s. 9826-9835
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Tidskriftsartikel (refereegranskat)abstract
- Enzyme promiscuity is evolutionarily advantageous to plants for gaining new enzyme functions when adapting to environmental challenges. However, this promiscuity can negatively affect the expression of genes encoding for plant enzymes in microorganisms. Here, we show that refining the promiscuity of flavonoid 3'-hydroxylase (F3'H) and 4'-O-methyltransferase (F4'OMT) improves (2S)-hesperetin production in Escherichia coli. First, we employed inverse molecular docking to screen a highly substrate-specific ThF3'H from Tricyrtis hirta, which could selectively convert 100 mg L-1 (2S)-naringenin to (2S)-eriodictyol but not (2S)-isosakuranetin, with a cytochrome P450 reductase from Arabidopsis thaliana. Second, we employed a directed evolution approach to restrict the promiscuity of MpOMT from Mentha x piperita. The strain harboring the MpOMT(S142V) mutant presented a remarkably increased preference for (2S)-eriodictyol. Finally, 27.5 mg L-1 (2S)-hesperetin was produced, while only minor amounts of (2S)-eriodictyol and (2S)-isosakuranetin accumulated as byproducts. This value represents a 14-fold increase in (2S)-hesperetin compared to the parental strain, along with a dramatic reduction in side products. Our work highlights the benefit of alleviating the promiscuity of plant enzymes when engineering production of natural products by microbial cell factories.
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| 13. |
- Liu, Wei, et al.
(författare)
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Pickering multiphase materials using plant-based cellulosic micro/nanoparticles
- 2024
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Ingår i: Aggregate. - 2692-4560.
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Forskningsöversikt (refereegranskat)abstract
- Pickering multiphase systems stabilized by solid particles have recently attracted increasing attention due to their excellent stability. Among various solid stabilizers, natural and renewable cellulosic micro/nanoparticles that are derived from agricultural and forestry sources have become promising candidates for Pickering stabilization due to their unique morphological features and tunable surface properties. In this review, recent progress on forming and stabilizing Pickering multiphase systems using cellulosic colloidal particles is summarized, including the physicochemical factors affecting their assembly at the interfaces and the preparation methods suitable for producing Pickering emulsions. In addition, relevant application prospects of corresponding Pickering multiphase materials are outlined. Finally, current challenges and future perspectives of such renewable Pickering multiphase systems are presented. This review aims to encourage the utilization of cellulosic micro/nanoparticles as key components in the development of Pickering systems, leading to enhanced performance and unique functionalities. image
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| 14. |
- Pan, Siqi, et al.
(författare)
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N-Bromosuccinimide as a p-type dopant for a Spiro-OMeTAD hole transport material to enhance the performance of perovskite solar cells
- 2021
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Ingår i: Sustainable Energy & Fuels. - : Royal Society of Chemistry. - 2398-4902. ; 5:8, s. 2294-2300
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Tidskriftsartikel (refereegranskat)abstract
- Low costN-bromosuccinimide (NBS) was applied as an effective p-type dopant in 2,2′,7,7′-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9-spirobifluorene (Spiro-OMeTAD), an important hole transport material (HTM) for perovskite solar cells (PSCs). At the optimum doping concentration, the hole mobility, conductivity, stability, and various performances of the devices were significantly improved, particularly the hole mobility increased by more than 3.5 times from 1.39 × 10−4cm2V−1s−1to 4.92 × 10−4cm2V−1s−1. This dopant prompted the power conversion efficiency (PCE) of the PSC device from 16.12% to 19.24% (0.1 cm2, AM 1.5G, 100 mW cm−2) with high stability.
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| 15. |
- Rai, Masna, et al.
(författare)
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Heat-related cardiorespiratory mortality : effect modification by air pollution across 482 cities from 24 countries
- 2023
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Ingår i: Environment International. - : Elsevier. - 0160-4120 .- 1873-6750. ; 174
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Tidskriftsartikel (refereegranskat)abstract
- Background: Evidence on the potential interactive effects of heat and ambient air pollution on cause-specific mortality is inconclusive and limited to selected locations. Objectives: We investigated the effects of heat on cardiovascular and respiratory mortality and its modification by air pollution during summer months (six consecutive hottest months) in 482 locations across 24 countries.Methods: Location-specific daily death counts and exposure data (e.g., particulate matter with diameters ≤ 2.5 µm [PM2.5]) were obtained from 2000 to 2018. We used location-specific confounder-adjusted Quasi-Poisson regression with a tensor product between air temperature and the air pollutant. We extracted heat effects at low, medium, and high levels of pollutants, defined as the 5th, 50th, and 95th percentile of the location-specific pollutant concentrations. Country-specific and overall estimates were derived using a random-effects multilevel meta-analytical model.Results: Heat was associated with increased cardiorespiratory mortality. Moreover, the heat effects were modified by elevated levels of all air pollutants in most locations, with stronger effects for respiratory than cardiovascular mortality. For example, the percent increase in respiratory mortality per increase in the 2-day average summer temperature from the 75th to the 99th percentile was 7.7% (95% Confidence Interval [CI] 7.6–7.7), 11.3% (95%CI 11.2–11.3), and 14.3% (95% CI 14.1–14.5) at low, medium, and high levels of PM2.5, respectively. Similarly, cardiovascular mortality increased by 1.6 (95%CI 1.5–1.6), 5.1 (95%CI 5.1–5.2), and 8.7 (95%CI 8.7–8.8) at low, medium, and high levels of O3, respectively.Discussion: We observed considerable modification of the heat effects on cardiovascular and respiratory mortality by elevated levels of air pollutants. Therefore, mitigation measures following the new WHO Air Quality Guidelines are crucial to enhance better health and promote sustainable development.
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| 16. |
- Xiao, Zhiqiang, et al.
(författare)
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Systematic Engineering of Saccharomyces cerevisiae Chassis for Efficient Flavonoid-7-O-Disaccharide Biosynthesis
- 2023
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Ingår i: ACS Synthetic Biology. - 2161-5063. ; 12:9, s. 2740-2749
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Tidskriftsartikel (refereegranskat)abstract
- Flavonoids are an essential class of secondary metabolites found in plants and possess various nutritional, medicinal, and agricultural properties. However, the poor water solubility of flavonoid aglycones limits their potential applications. To overcome this issue, glycosylation is a promising approach for improving water solubility and bioavailability. In this study, we constructed a flavonoid-7-O-disaccharide biosynthetic pathway with flavonoid aglycones as substrates in Saccharomyces cerevisiae. Subsequently, through metabolic engineering and promoter strategies, we constructed a UDP-rhamnose regeneration system and optimized the UDP-glucose (UDPG) synthetic pathway. The optimized strain produced up to 131.3 mg/L eriocitrin. After this, the chassis cells were applied to other flavonoids, with substrates such as (2S)-naringenin, (2S)-hesperetin, diosmetin, and (2S)-eriodictyol, which resulted in the synthesis of 179.9 mg/L naringin, 276.6 mg/L hesperidin, 249.0 mg/L neohesperidin, 30.4 mg/L diosmin, and 100.7 mg/L neoeriocitrin. To the best of our knowledge, this is the first report on the biosynthesis of flavonoid-7-O-disaccharide.
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| 17. |
- Xu, Yilin, et al.
(författare)
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Analysis of Thermal Stress in a Solid Oxide Fuel Cell Due to the Sulfur Poisoning Interface of the Electrolyte and Cathode
- 2021
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Ingår i: Energy and Fuels. - : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 35:3, s. 2674-2682
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Tidskriftsartikel (refereegranskat)abstract
- The interface of an electrolyte and cathode strongly determines the oxygen reduction reaction and cell stability, but it is susceptible to sulfur impurities like SO2 in air. In this study, a 3D solid oxide fuel cell model is developed based on experimental characterization to reveal sulfur-deactivating active cathodes. The results indicate that both the average values for electric and ionic current densities drastically decrease after sulfur poisoning; meanwhile, their distributions are also changed, suggesting that the involved oxygen reduction reaction is detrimentally affected. Moreover, the temperature decreases after poisoning due to electrochemical reaction slowdown near the interface of the active cathode and electrolyte. The pronounced temperature changes together with differences in the thermal expansion coefficient of neighboring components, further resulting in uneven stress distributions at the active cathode, possibly bringing out cracks and bending. Thermal stresses are reduced after sulfur poisoning, especially for the third principal stress, which produces a decrement of 154 MPa. The visualized results of the current density, temperature, and stresses are helpful to understand the sulfur poisoning behavior and also to better understand the internal changes of some crucial electrochemical processes beneficial for further optimization of the microstructural stability.
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| 18. |
- Zhang, Siqi, et al.
(författare)
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Systems Metabolic Engineering of Saccharomyces cerevisiae for the High-Level Production of (2 S )-Eriodictyol
- 2024
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Ingår i: Journal of Fungi. - 2309-608X. ; 10:2
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Tidskriftsartikel (refereegranskat)abstract
- (2S)-eriodictyol (ERD) is a flavonoid widely found in citrus fruits, vegetables, and important medicinal plants with neuroprotective, cardioprotective, antidiabetic, and anti-obesity effects. However, the microbial synthesis of ERD is limited by complex metabolic pathways and often results in a low production performance. Here, we engineered Saccharomyces cerevisiae by fine-tuning the metabolism of the ERD synthesis pathway. The results showed that the ERD titer was effectively increased, and the intermediate metabolites levels were reduced. First, we successfully reconstructed the de novo synthesis pathway of p-coumaric acid in S. cerevisiae and fine-tuned the metabolic pathway using promoter engineering and terminator engineering for the high-level production of (2S)-naringenin. Subsequently, the synthesis of ERD was achieved by introducing the ThF3 ' H gene from Tricyrtis hirta. Finally, by multiplying the copy number of the ThF3 ' H gene, the production of ERD was further increased, reaching 132.08 mg L-1. Our work emphasizes the importance of regulating the metabolic balance to produce natural products in microbial cell factories.
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| 19. |
- Zhang, Xiaoqiang, et al.
(författare)
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Thermal stress analysis at the interface of cathode and electrolyte in solid oxide fuel cells
- 2020
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Ingår i: International Communications in Heat and Mass Transfer. - : Elsevier BV. - 0735-1933. ; 118
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Tidskriftsartikel (refereegranskat)abstract
- A benign thermal stress in solid oxide fuel cell is of great importance for its stability and the interfaces between different components suffer from unexpected risks of instability such as electrode delamination and crack due to varying thermal expansion coefficients. Besides, chromium poisoning cathode materials leads to phase changes, which possibly induces thermal stresses at the interface of electrolyte and cathode. A three dimensional model at the microscale level is thus developed to unravel the effect of thermal stress on the interface. The model is constructed by governing equations including heat, species, momentum, ion and electronic transportation. The contact modes between the active cathode and electrolyte are studied to reveal the cell performance and thermal stresses, which are strongly related to the number of contact sites and the contact area. Moreover, chromium poisoning the contact causes the disordered distribution of thermal stresses with the increase of the contact sites, worsening the cell current density and durability. The resulting conclusions are expected to offer a solution to avoid possible fatal mechanical failure due to unfavorable interface design and chromium attack.
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| 20. |
- Zhu, Lianghong, et al.
(författare)
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Phase Current Reconstruction Error Suppression Method for Single DC-Link Shunt PMSM Drives at Low-Speed Region
- 2022
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Ingår i: IEEE transactions on power electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0885-8993 .- 1941-0107. ; 37:6, s. 7067-7081
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Tidskriftsartikel (refereegranskat)abstract
- The extensive application of vector phase shift modulation method in permanent magnet synchronous motor drive systems with single dc-link current sensor results in obvious current ripple in the low-speed region. The patterns of these ripples vary greatly in different sectors, leading to nonnegligible phase current reconstruction errors. In this article, an estimation of the local average current change rate (ELAC(2)R) based reconstruction error suppression method within the switching cycle is proposed to resolve this problem. By comparing the actual and the ideal sampling points, the increase of current ripple and the reconstruction error caused by the combination of the vector phase shift and the single current sensor sampling in the low-speed region are modelled and analyzed. Then according to equivalent modelling of the current ripple between the ideal and the actual sampling points, the more accurate phase current information can be quickly obtained based on the sampling value. The compensation process is significantly simplified and the computation burden of the processor is reduced. Experimental results show that the performance of current reconstruction can be improved effectively with less harmonic content with the proposed method.
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| 21. |
- Zhu, Zhenyu, et al.
(författare)
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Coupling life prediction of bending very high cycle fatigue of completion strings made of different materials using deep wise separable convolution
- 2024
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Ingår i: Fatigue & Fracture of Engineering Materials & Structures. - : WILEY. - 8756-758X .- 1460-2695.
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Tidskriftsartikel (refereegranskat)abstract
- This article predicts bending very high cycle fatigue (VHCF) life of three typical nickel-based alloys SM2550, BG2532, and G3 used for completion strings. Fatigue tests were conducted on the three alloys using an ultrasonic fatigue system at a frequency of 20 kHz. The results showed that the fatigue strength ranges of the three alloys were markedly different, reflecting their different sensitivities to fatigue loading. Scanning electron microscope observations revealed numerous fatigue crack origins with internal decohesion in the fatigue source region. To achieve unified prediction of the fatigue life for the three alloys, a prediction model based on deep learning was built with inputs including fatigue initiation quantity, cleavage facet size, and other fatigue fracture characteristics. It was found that single source feature was insufficient to obtain satisfactory prediction accuracy for all alloys, while multifeature coupling integration could significantly improve the prediction precision, enabling reliable prediction of alloy fatigue life. This study provides new insights into bending VHCF life prediction. This article predicts bending VHCF life for three completion strings. Bending VHCF life model utilizing deep wise separable convolution was established. Deep learning can effectively integrate with bending VHCF analyses.
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