Journal of Physical Chemistry C
·
2021
·
IF 4.126
Tu Lan,Qian Qiao,Fangxu Hu,De Li,Yong Chen
The electrochemical signals are very important to analyze and regulate the electrochemical systems, and the electrochemical oscillation is a newly discovered electrochemical signal in Li-ion batteries (LIBs), including the voltage and current oscillations. In this work, the Li4Ti5O12 was prepared using a home-made spray-drying instrument and high-temperature sintering, and its electrochemical oscillation was studied in LIBs. The electrochemical oscillation arose when the as-prepared Li4Ti5O12 precursor was sintered in a powder (not pellet) form, and it became stronger by reducing the lithium content in Li4Ti5O12. There are two types of electrochemical oscillation as a single-period oscillation or a double-period oscillation, and they can be transformed through varying the operating temperature, the current rate, and the conductive agent ratio, which might be owing to the electrochemical kinetics of Li4Ti5O12 electrodes. Combining the sintered forms and the X-ray photoelectron spectroscopy results, whether there is some fresh surface (formed by grinding the sintered pellet) becomes a typical difference between the powder-sintered and pellet-sintered Li4Ti5O12, which would affect the nucleation step and the reaction kinetics, and we proposed a possible reaction process of the electrochemical oscillation during the galvanostatic charging process of Li4Ti5O12 in LIBs.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Soft Matter
·
2024
·Vol. 20
·期 21
·4246-4256
·
IF 2.9
Yuying Sun,Yanli Men,Shiyu Liu,Xiuxiu Wang,Chensha Li
The self-oscillation of objects that perform continuous and periodic motions upon unchanging and constant stimuli is highly important for intelligent actuators, advanced robotics, and biomedical machines. Liquid crystalline elastomer (LCE) materials are superior to traditional stimuli-responsive polymeric materials in the development of self-oscillators because of their reversible, large and anisotropic shape-changing ability, fast response ability and versatile structural design. In addition, fiber-shaped oscillators have attracted much interest due to their agility, flexibility and diverse oscillation modes. Herein, we present a strategy for fabricating fiber-shaped LCE self-oscillators using soft tubes as molds. Through the settlement of different configuration states of the soft tubes, the prepared fiber-shaped LCE oscillators can perform continuous rotational self-oscillation or up-and-down shifting self-oscillation under constant light stimuli, which are realized by photoinduced repetitive self-winding motion and self-waving motion, respectively. The mechanism of self-oscillating movements is attributed to the local temperature oscillation of LCE fibers caused by repetitive self-shadowing effects. LCE self-oscillators can operate stably over many oscillating cycles without obvious performance attenuation, revealing good robustness. Our work offers a versatile way by which LCE self-oscillators can be conveniently designed and fabricated in bulk and at low cost, and broadens the road for developing self-oscillating materials for biological robotics and health care machines.
研究领域:
材料科学
·
智能机器人
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2016
·
IF 4.803
Juan Chen,Lin Hu,Gang Hu,Yu Zhang,Yuanyuan Hu,Jimei Song
In the analytical field, previous applications of chemical oscillation focused on quantitative analysis. We report in this paper a novel qualitative method electrochemically distinguishing two positional isomers by utilizing their perturbation effects on a catalyzed Briggs–Rauscher (BR) oscillation. The catalyst in the system is a macrocyclic nickel (II) complex NiL(ClO 4 ) 2 , where the ligand L in the complex is 5,7,7,12,14,14-hexemethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene. The experimental results indicated that addition of cyclohexane-1,3-dione (1,3-CHD) or 1,4-cyclohexanedione (1,4-CHD) could affect the profiles of potentiometric oscillations, but their changes in the profiles are greatly different. When 1,3-CHD was injected into the oscillating system, there was an initial spiking of the oscillations, accompanying by quenching of oscillations before the regeneration of oscillations. While 1,4-CHD was injected into the dynamic mixture, the oscillatory system responded to the perturbation with only slight decrease followed by a sharp increase in the potential, before it resumed to its normal oscillation state. The perturbation of 1,3-CHD involves inhibition time, whereas the perturbation of 1,4-CHD does not. Hence these two positional isomers could be distinguished by using their different perturbation effects on a BR dynamic system in the range of 9.0 × 10 −4 to 8.0 × 10 −3 M. Our assumption is that, perturbation of 1,3-CHD on the oscillating system involves a radical oxidization process to produce carboxylic acid, whereas perturbation of 1,4-CHD assumes idiodation and elimination steps to form 1,4-benzoquinone. Such different perturbation mechanisms are responsible for the difference in potentiometric oscillation profiles change. This hypothesis was confirmed by products analysis by FTIR and UV spectra.
研究领域:
分析化学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2023
·
IF 4.6
Hua Yang,Zemin An,Yuanjie Xu,Lizhi Wu,Li Tan,Yu Tang
The restructuring of a catalyst under working conditions has been recognized as a critical factor that can significantly impact their performance in recent years. In this study, we investigate the behavior of a highly dispersed Ni supported on TiO 2 (P25) catalyst during the partial oxidation of methane (POM) to produce syngas. Our results reveal a distinct oscillation phenomenon in the catalyst's performance over time. The simultaneous oscillations of rapid deactivation and activation are observed, while the catalyst remains active for continuous POM reaction. Comprehensive characterizations suggest that this deactivation is not caused by traditional deactivation mechanisms with coke formation or Ni sintering. The formation of inactive NiTiO 3 results in catalyst deactivation, which is formed between Ni and TiO 2 support in the reductive atmosphere of POM products under high temperature due to strong metal-support interaction (SMSI). The simultaneous presence of oxidative and reductive atmospheres of the reactants and products in the POM reaction leads to the generation or demise of NiTiO 3 . The dynamic change of the Ni active sites during the in-situ reaction leads to the oscillation of the catalytic activity. This study sheds new light on the importance of SMSI in understanding the behavior of catalysts under working conditions.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2018
·
IF 3.235
Wangning Zhang,Waqar Uddin,Gang Hu,Lin Hu,Zhaohui Fang
A novel method for identification of four isomers of dihydroxynaphthalene (DHN) was reported by their different perturbation effects on a Briggs-Rauscher (BR) oscillating system. In the system, macrocyclic nickel (II) complex NiL(ClO 4 ) 2 is used as the catalyst, where the ligand L in the complex is 5,7,7,12,14,14‑hexemethyl‑1,4,8,11‑tetraazacyclotetradeca‑4,11‑diene. By putting equal amount of the same concentrations of four isomers (1,4‑dihydroxynaphthalene (1,4-DHN), 1,5‑dihydroxynaphthalene (1,5-DHN), 2,3‑dihydroxynaphthalene (2,3-DHN) and 2,7‑dihydroxynaphthalene (2,7-DHN)) into BR system, the system could or couldn't be perturbed, being reflected in quite different oscillating behaviors after addition of isomers. These four isomers were identified in their concentration range of 5.0 × 10 −6 to 2.5 × 10 −4 mol/L. An explanation of such perturbation mechanism is that, 1,4-DHN couldn't be oxidized by BR matrix, but 1,5-DHN, 2,3-DHN and 2,7-DHN could be oxidized by HOO to yield 5‑Hydrox‑1,4‑naphthoquinone, phthalic acid and 6,7‑dihydroxyperylene‑1,12‑quinone (DHPQ), respectively.
研究领域:
分析化学
·
物理化学
·
化学生物学
·
反应动力学
·
分子识别
✓ 已验证
DOI
高影响因子
ENERGY
·
2025
·
IF 9.4
Delin Lyu,Xuanjie Cui,Yuanqing Qu,Zhengyang Liu,Xiangning Liu,Zhen Huang,Dong Han
Increasing the compression ratio in spark-ignition (SI) engines improves thermal efficiency but raises knock risk. Knock resistance is measured by Research Octane Number (RON) in Cooperative Fuel Research (CFR) engines under standard conditions, which differ from modern SI engines. The CFR engine's knock sensor, fitted with a low-pass filter, fails to accurately detect high-frequency knock oscillations, making conventional RON inadequate for assessing knock resistance in modern engines. To address this, the CFR engine was modified by replacing the knock sensor with a cylinder pressure sensor for direct combustion pressure measurement and upgrading the carburetor to electronic fuel injection. Under stoichiometric conditions, the Maximum Amplitude of Pressure Oscillation (MAPO) and Integral of Modulus of the Pressure Oscillation (IMPO) methods were applied to evaluate PRF blends with RONs of 88–100. Strong correlations were observed between the fuels RON and both IMPO and MAPO measurements, with coefficients of determination of 0.98 and 0.99, respectively. This study also analyzed error sources and quantified measurement inaccuracies in both methods, with IMPO showing lower absolute error of RON and variability. To verify the reliability of the IMPO and MAPO methods in evaluating high-octane fuels, particularly those with RON >100, these methods were applied to test TRFs and oxygenated fuel blends with RONs of 94–108. Results showed deviations from conventional measurements; however, for fuels with RON >100, both methods effectively distinguished fuel knock resistance capacity. Additionally, IMPO and MAPO captured the knock resistance improvements for the addition of ethanol and 2-MF in gasoline blends.
研究领域:
机械工程
·
汽车工程
·
燃料技术
·
燃烧分析
·
传感器技术
✓ 已验证
产品关联
DOI
高影响因子
Micromachines
·
2022
·Vol. 13
·期 11
·1949
·
IF 3.523
Chao Chang,Yaoguang Yang,Lilin Pei,Zhaoyang Han,Xiu Xiao,Yulong Ji
With the rapid development of electronic technologies towards high integration, high power and miniaturization, thermal management has become an increasingly important issue to guarantee the reliability and service life of electronic devices. The oscillating heat pipe (OHP), which was governed by thermally excited oscillating motion, was considered as a promising technology to dissipate high-density heat and had excellent application prospects in many important industrial processes. A flat-plate OHP, however, was fabricated by traditional welding methods, which were difficult and inefficient, resulting in increasing the cost and wasting the production time. In this work, we adopted a new metal 3D printing technology to develop an aluminum flat-plate OHP, which made it facile to build complex inner channels with high-precision molding at one time. AlSi10Mg powders, as raw materials, were selectively melted and solidified to form the container of the flat-plate OHP. The sintered inner surface presented excellent wettability to the working fluid, which facilitated the evaporation of the working fluid. Acetone was chosen as the working fluid, and the filling ratios with a range of 40–70% were loaded into the flat-plate oscillating heat pipe to analyze its effect on heat transfer performance. It was found that the 3D-printed flat-plate OHP with a 60% filling ratio had a better heat transfer performance and a lower thermal resistance, and it was able to work properly in both vertical and horizontal operation modes. The 3D-printed flat-plate OHP had been successfully applied for the thermal management of high-power LEDs, and the results showed that the temperature of LEDs was maintained within 60 °C, and its service life was prolonged.Keywords:3D printing;oscillating heat pipe;thermal resistance;heat transfer performance
研究领域:
电子工程
·
热管理技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymers
·
2023
·Vol. 15
·期 2
·414
·
IF 5
Zhaoyang Han,Chao Chang
As flexible electronic technologies rapidly developed with a requirement for multifunction, miniaturization, and high power density, effective thermal management has become an increasingly important issue. The oscillating heat pipe, as a promising technology, was used to dissipate high heat fluxes and had a wide range of applications. In this paper, we reported the fabrication and heat transfer performance evaluation of a polymer-based flexible oscillating heat pipe (FOHP) prepared using 3D printing technology. The 3D-printed inner surface presented excellent wettability to the working fluid, which was beneficial for the evaporation of the working fluid. Ethanol was selected as the working fluid, and the influence of the filling ratios range of 30–60% on heat transfer performance was analyzed. It was found that a 3D-printed FOHP with a filling ratio of 40% presented the best heat transfer performance with the lowest thermal resistance, and the fabricated heat pipes could be easily bent from 0° to 90°. With the best filling ratio, the thermal resistance of the FOHPs increased with larger bending angles. In addition, the 3D-printed FOHP was successfully applied for the thermal management of flexible printed circuits, and the results showed that the temperature of flexible printed circuits was kept within 72 °C, and its service life was guaranteed.Keywords:3D printing;flexible oscillating heat pipe;thermal resistance;thermal performance
研究领域:
热管理技术
·
材料科学与工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Neural Regeneration Research
·
2024
·Vol. 20
·期 4
·1164
·
IF 5.9
Wang Pengfei,Bi Yuewei,Li Min,Chen Jiazhi,Wang Zhuyong,Wen Huantao,Zhou Ming,Luo Minjie,Zhang Wangming
Long-term levodopa administration can lead to the development of levodopa-induced dyskinesia. Gamma oscillations are a widely recognized hallmark of abnormal neural electrical activity in levodopa-induced dyskinesia. Currently, studies have reported increased oscillation power in cases of levodopa-induced dyskinesia. However, little is known about how the other electrophysiological parameters of gamma oscillations are altered in levodopa-induced dyskinesia. Furthermore, the role of the dopamine D3 receptor, which is implicated in levodopa-induced dyskinesia, in movement disorder-related changes in neural oscillations is unclear. We found that the cortico-striatal functional connectivity of beta oscillations was enhanced in a model of Parkinson’s disease. Furthermore, levodopa application enhanced cortical gamma oscillations in cortico-striatal projections and cortical gamma aperiodic components, as well as bidirectional primary motor cortex (M1) ↔ dorsolateral striatum gamma flow. Administration of PD128907 (a selective dopamine D3 receptor agonist) induced dyskinesia and excessive gamma oscillations with a bidirectional M1 ↔ dorsolateral striatum flow. However, administration of PG01037 (a selective dopamine D3 receptor antagonist) attenuated dyskinesia, suppressed gamma oscillations and cortical gamma aperiodic components, and decreased gamma causality in the M1 → dorsolateral striatum direction. These findings suggest that the dopamine D3 receptor plays a role in dyskinesia-related oscillatory activity, and that it has potential as a therapeutic target for levodopa-induced dyskinesia.
研究领域:
神经科学
·
药理学
·
帕金森病
✓ 已验证
DOI
高影响因子
ULTRASONICS SONOCHEMISTRY
·
2015
·
IF 4.321
Xiaoming Luo,Limin He,Hongping Wang,Haipeng Yan,Yahua Qin
The motion of a single water droplet in oil under ultrasonic irradiation is investigated with high-speed photography in this paper. First, we described the trajectory of water droplet in oil under ultrasonic irradiation. Results indicate that in acoustic field the motion of water droplet subjected to intermittent positive and negative ultrasonic pressure shows obvious quasi-sinusoidal oscillation. Afterwards, the influence of major parameters on the motion characteristics of water droplet was studied, such as acoustic intensity, ultrasonic frequency, continuous phase viscosity, interfacial tension, and droplet diameter, etc. It is found that when the acoustic intensity and frequency are 4.89 W cm −2 and 20 kHz respectively, which are the critical conditions, the droplet varying from 250 to 300 μm in lower viscous oil has the largest oscillation amplitude and highest oscillation frequency.
研究领域:
物理学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2023
·
IF 19
Xinpeng Che,Ting Wang,Bailang Zhang,Zhuanzhuan Zhai,Yijun Chen,Danfeng Pei,Anle Ge,Mingjie Li,Chaoxu Li
Harvesting electricity from ubiquitous atmospheric moisture has drawn growing research attention. Despite great advances, moisture generators still suffer from performance decay during long-term service. Recently, self-oscillating actuators driven by humidity gradience have attracted great interests, which may give a clue to harvest energy persistently via electromagnetic induction. In order to combine high electric conductivity with self-oscillating actuators, bimorph composites of 2D conductive MXene with liquid metal (i.e., EGaIn) are designed. In presence of marine alginate, EGaIn droplets can be encapsulated by MXene nanosheets in their suspension. And simple liquid-casting can produce biomorph actuating films with top MXene-rich layer and bottom EGaIn-rich layer of self-sintered EGaIn droplets. When exposing to a humidity gradience (e.g., 20% cm −1 ), this biomorph actuator can oscillate persistently with an actuating speed of ≈260° s −1 and a frequency of ≈0.5 Hz, while without any human intervention. Under a magnetic field (e.g., intensity ≈0.5 T), this self-oscillating behavior can generate an alternating faradic current with an amplitude of at least 1360 µA m −2 . Thus, this study may not only provide an alternative pathway for producing self-oscillating and conductive actuators, but also offer a new strategy for persistent energy harvest from atmospheric moisture.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2020
·
IF 3.871
Ajuan Song,Yiming Ji,Chao Li,Yijun Cao
Microbubbles are applied in various industrial fields. The bubble size is crucial to the process efficiency. Recent studies have shown that the replacement of steady air supply by oscillatory air supply could significantly decrease the sizes of bubbles formed from submerged orifices, owing to the increased momentum force, which is a lifting force for bubble formation. However, the responses of the momentum force to the oscillatory air supply are not yet clear. This study provides a qualitative model for the momentum force as a function of the characteristics of the oscillatory air supply, including the switching frequency, on/off time ratio, and gas flow rate. The model was experimentally validated by investigating the variations in the momentum force with the characteristics of the oscillatory air supply. In addition, the correlation between the momentum force and bubble size under the oscillatory air supply was also investigated.
研究领域:
化学工程
·
流体力学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）