4,156 research outputs found
Skidding and cage whirling of angular contact ball bearings: Kinematic-hertzian contact-thermal-elasto-hydrodynamic model with thermal expansion and experimental validation
No full textThe occurrence of skidding and overskidding behaviour is likely to scratch rolling element raceways and lead to a significant temperature rise and thermal deformation. The ball-cage interaction and cage whirling motion are likely to oscillate as this skidding is aggravated. To address the damage problems introduced by skidding behaviour, a kinematic-Hertzian contact thermal-elasto-hydrodynamic (KH-TEHD) model with a 5-layer loop structure is proposed. Various factors are considered in the model, including the dynamic beahviour of bearing components, quasi-static analysis on bearing load distribution and deformation of bearing components, and the miscellaneous forces (unbalanced force, collision tangential friction, drag force) acting on the ball and cage. Ball-raceway lubrication, lubricant temperature rise, thermal expansion of shaft and bearing housings, and hydrodynamic pressure acting between the cage surface and guide-ring surface are established in this paper. A 7307AC bearing experimental study under varying operating speeds, axial loads and two lubricating conditions is conducted to validate the accuracy and effectiveness of the KH-TEHD model. The superiority of the developed model is illustrated by comparison with previous models, and the results suggest that the thermal expansion and cage-guide ring hydrodynamic pressure cannot be ignored. After comparisons with literature results, it is found that the overskidding degree is approximately proportional to the square of the bearing size under the same level of operating speed. The maximum thermal deformation at the bearing raceway under starvation lubrication reaches 4 times the ball-raceway clearance. The cage simulation results indicate that the cage whirling oscillation amplitude increases with increasing operating speed and unbalanced mass and generally decreases with increasing axial load. The proposed model and discussion of the results are useful for mitigating the skidding degree under certain conditions and avoiding cage instability and wear
Ran liao min hua tai yang neng dian chi de guang pu xiang ying zeng qiang
No full textChang, Shuai = 染料敏化太陽能電池的光譜響應增強 / 常帥.Thesis Ph.D. Chinese University of Hong Kong 2015.Includes bibliographical references (leaves 125-130).Abstracts also in Chinese.Title from PDF title page (viewed on 02, November, 2016).Chang, Shuai = Ran liao min hua tai yang neng dian chi de guang pu xiang ying zeng qiang / Chang Shuai
Energy-Efficient Train Operation: Conclusions and Future Work
No full textThis chapter gives the basic conclusions about energy-efficient train operation covering energy-efficient train driving, energy-efficient train timetabling, regenerative braking, energy storage systems and power supply networks. Future work that will develop energy-efficient train operation further include the interaction of connected driver advisory systems (C-DAS) and automatic train operation (ATO) with railway traffic management systems, cooperative train control in platoons of virtually coupled trains, digital twin technology and particularly its application to power supply systems, and the interaction between the railway network with the electrical power grid and renewable energy generation.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Transport and Plannin
Russula hainanensis (Russulaceae, Russulales), a new species from tropical China
No full textHan, Yun-Xiao, Liang, Zhi-Qun, Jiang, Shuai, Zeng, Nian-Kai (2022): Russula hainanensis (Russulaceae, Russulales), a new species from tropical China. Phytotaxa 552 (1): 35-50, DOI: 10.11646/phytotaxa.552.1.
On blowup techniques and the pluricomplex Green's function
No full textThe pluricomplex Green's functions on a compact K ahler manifold have been extensively studied over the past decades. Following and generalizing the blow up techniques in [PS12], we use pluripotential theory to show the existence and uniqueness of pluricomplex Green's functions with two types of prescribed singularities at a finite number of interior points.Ph.D.Includes bibliographical referencesby Shuai Jian
Fig. 5 in Phenanthrene, 9,10-dihydrophenanthrene and bibenzyl enantiomers from Bletilla striata with their antineuroinflammatory and cytotoxic activities
No full textFig. 5. Plausible Biogenetic Pathway of Compounds 1–13.Published as part of Sun, Mo-Han, Ma, Xian-Jie, Shao, Si-Yuan, Han, Shao-Wei, Jiang, Jian-Wei, Zhang, Jian-Jun & Li, Shuai, 2021, Phenanthrene, 9,10-dihydrophenanthrene and bibenzyl enantiomers from Bletilla striata with their antineuroinflammatory and cytotoxic activities, pp. 1-14 in Phytochemistry (112609) 182 on page 10, DOI: 10.1016/j.phytochem.2020.112609, http://zenodo.org/record/829142
Fig. 2 in Phenanthrene, 9,10-dihydrophenanthrene and bibenzyl enantiomers from Bletilla striata with their antineuroinflammatory and cytotoxic activities
No full textFig. 2. Key HMBC (→) and COSY (bold) correlations of compounds 1, 2, 4, 7, 9, 11 and 13.Published as part of Sun, Mo-Han, Ma, Xian-Jie, Shao, Si-Yuan, Han, Shao-Wei, Jiang, Jian-Wei, Zhang, Jian-Jun & Li, Shuai, 2021, Phenanthrene, 9,10-dihydrophenanthrene and bibenzyl enantiomers from Bletilla striata with their antineuroinflammatory and cytotoxic activities, pp. 1-14 in Phytochemistry (112609) 182 on page 4, DOI: 10.1016/j.phytochem.2020.112609, http://zenodo.org/record/829142
Treatment of Atrophic Acne Scarring with Fractional Microplasma Radiofrequency: A Multicentric Experience
No full textBackground: Atrophic scarring is a severe form-disfiguring sequela of acne, which can lead to negative effect on patients' life. Fractional microplasma radiofrequency (RF) has emerged as a promising modality, leveraging dermal fibroblast remodeling to enhance aesthetic results for scars and hyperpigmentation. This study evaluates the efficacy and safety of high-power fractional microplasma RF for atrophic acne scars, considering patient tolerance to procedural discomfort. Methods: In this prospective study, 95 Chinese patients with atrophic facial acne scars underwent three sessions of fractional microplasma RF treatment, with assessments at 1, 3, and 6 months post-treatment. Patients were categorized based on treatment power: Group A (50-70 W) and Group B (70-85 W). Efficacy was determined by three independent dermatologists using digital photographs and Echelle d'Evaluation Clinique des Cicatrices d'Acn & eacute; (ECCA) scores, and patient-reported outcomes gauged satisfaction levels. Results: Eighty-six patients completed the study. Significant improvements were observed, with a reduction in ECCA scores from 107.21 to 42.27 (P<0.05), demonstrating notable scar amelioration across both groups, albeit with a superior outcome in Group B. All patients experienced transient side effects such as pain, erythema, and edema, deemed tolerable with no long-term adverse effects reported. The treatment was well-received, with high satisfaction rates, underscoring its efficacy and acceptable safety profile. Conclusion: Fractional microplasma RF therapy, particularly at higher power settings, is an effective and safe option for treating atrophic acne scars, offering significant aesthetic improvement with manageable discomfort. This modality presents a valuable addition to acne scar management strategies, especially for patients with darker skin tones seeking minimal downtime and reduced risk of hyperpigmentation. (c) 2024 The Author(s). Published by Elsevier Ltd on behalf of British Association of Plastic, Reconstructive and Aesthetic Surgeons. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/
Studies on Zhong Jun Shuai in the middle stage of State of Jin.
No full textFor a period about two hundred and thirty years before 479 BC. Jing holds supreme power over all neighbouring hostile countries and protected emperor Zhou. Only until Han\uef\ub9Zhao\uef\ub9Wei started civil strife and Jing was torn apart, then did Zhou's empire fall.
The article below is to discuss how Jing came to power with the setup of Zhong Jun Shuai\uef\ubcand several political and civil issues raised during that period of time
FIGURE 1 in Russula hainanensis (Russulaceae, Russulales), a new species from tropical China
No full textFIGURE 1. Collection sites (red dots) of Russula hainanensis.Published as part of Han, Yun-Xiao, Liang, Zhi-Qun, Jiang, Shuai & Zeng, Nian-Kai, 2022, Russula hainanensis (Russulaceae, Russulales), a new species from tropical China, pp. 35-50 in Phytotaxa 552 (1) on page 36, DOI: 10.11646/phytotaxa.552.1.3, http://zenodo.org/record/667321
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