Influence of Solution Concentrations on Surface Morphology and Wettability of ZnO Thin Films

Jianguo Lv,Changlong Liu,Feng Wang,Zhitao Zhou,Zhenfa Zi,Yuan Feng,Xiaoshuang Chen,Feng Liu,Gang He,Shiwei Shi,Xueping Song,Zhaoqi Sun 대한금속·재료학회 2013 ELECTRONIC MATERIALS LETTERS Vol.9 No.2

ZnO thin films were grown on silicon substrates using a hydrothermal method. The XRD patterns show that all of the peaks can be attributed to the wurtzite structures of ZnO. The TC value of (002) plane and average crystal size increase first and then decrease with the increase of solution concentration. SEM and AFM results show that many dense hexagonal cylinder particles have been observed on the surface of the thin films, which grown at 0.08 and 0.10 mol/L. The surface roughness of the thin films deposited at 0.06,0.08, 0.10, and 0.12 mol/L are 24.5, 38.3, 32.0, and 39.4 nm, respectively. Surface wettability results show that the preferential orientation along c-axis and surface roughness contribute significantly to the hydrophobicity. The reversible switching between hydrophobicity and hydrophilicity is related to the synergy of the transition of wetting model, surface crystal structure, and surface roughness.

SOC balance‑based decentralized control strategy for hybrid energy storage in integrated power systems

Xueping Gao,Lijun Fu,Yan Zhang,Feng Ji 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.12

The hybrid energy storage systems (HESSs) in vessel integrated power systems can support pulse load and improve system stability. However, the unbalanced SOC of different energy storage devices can cause over-charge and over-discharge which damages the energy storage devices and affects the stable operation of the entire system, especially when there are multiple groups of HESSs. Therefore, a decentralized control strategy for the HESSs in integrated power systems (IPSs) based on extended droop control combined with SOC balance control is proposed in this paper. In the proposed strategy, SOC recovery control is introduced to the virtual capacitance droop coefficient of the supercapacitor, and SOC equalization control is introduced to the virtual resistance droop coefficient of the lithium battery to adjust the output characteristics of the HESS according to the SOC. Then the frequency response characteristics are analyzed and the stability of the system is calculated. Finally, the hardware in loop simulation is conducted to verify the effectiveness of the proposed strategy. Comparisons show that the proposed strategy can compensate for the pulse load according to the responding characteristics of the HESS and achieve SOC balance between different energy storage devices under various working conditions.

A Demand Side Management Strategy to Reduce the Impact of High Power Pulse Load Integration

Gao Xueping,Zhang Yan,Ji Feng,Fu Lijun 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.5

High pulsed power loads (HPPLs) are highly non-linear and can cause signifi cant stability and power quality issues in a microgrid. Developing alternative methods for controlling and analyzing the microgrid with multiple HPPLs will provide insight into tradeoff s that can be made during the design phase. In this paper, a demand side management strategy of HPPLs in a microgrid is formulated. Firstly, the HPPLs are divided into energy storage connected high power pulse loads (EHPPLs) and direct connected high power pulse loads (DHPPLs) according to the power use of the back-end loads, and the energy management models of both the EHPPLs and the DHPPLs are built. Then the demand side management strategy to minimize the impacts of running HPPLs is proposed. Finally, three typical cases are studied to verify the fl exibility and eff ectiveness of the proposed method. The simulation and experiment results indicate that the proposed strategy can eff ectively reduce the peak power demand of the HPPLs, thus reducing the impact on the microgrid

Changes in Properties of White Shrimp (Litopenaeus vannamei) Protein during Thermal Denaturation

Ruichang Gao,Xueping Feng,Wenwen Li,Li Yuan,Jing Ge,Daoli Lu,Bin Chen,Gang Yu 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.1

Changes in white shrimp (Litopenaeus vannamei) protein during thermal denaturation were studied using Raman spectroscopy and isotopic H/D exchange. Denaturation of shrimp protein began after heating for 10 min at 50oC. A decrease in the percentage of α-helices accompanied by an increase in the percentage of β-sheets occurred while the total percentage of disordered structures increased. With extension of the exchange time, the relative intensity of the O-D bond increased, accompanied by a higher relative O-D bond intensity for heated shrimp, compared with unheated shrimp. H/D exchange revealed a higher rate of deuteration kinetics in heated shrimp than for unheated shrimp, especially during the first 2 h, consistent with water loss from denatured white shrimp protein. Physical property changes in muscle tissue can be caused by changes in hydrogen bonding and hydrophobicity during thermal processes.

Optimal Operation Schedule Strategy of High-power Pulsed Loads in Shipboard Power System

Zhang Yan,Ji Feng,Gao Xueping,Ma Fan,Hu Qi 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.4

With the vigorous development of the scientifi c and technological revolution, new military and engineering loads with high power and pulse characteristics are becoming reality for the shipboard power system (SPS) application. These loads are usually called high-power pulsed loads (HPPLs) because of their high peak power, low average power and short cycle time. The HPPLs can cause voltage drop and even system instability to the SPS, thus bringing severe challenges to their power supplying system. To address these issues, an optimal operation schedule of HPPLs in SPS is studied in this paper. Firstly, the models of HPPLs for SPS power optimization are proposed based on the real back-end load connection way of them. Then the mixed integer programming problem aiming at maximizing the operation effi ciency of the HPPLs within the SPS support capability is constructed. Finally, some typical cases are studied to verify the fl exibility and eff ectiveness of the proposed strategy. The results indicate that the proposed strategy can eff ectively maximize the operational effi ciency of HPPLs in the SPS, and the superiority becomes more obvious as the number of HPPLs increases.

Computational fluid dynamics simulation of hydrodynamics in an uncovered unbaffled tank agitated by pitched blade turbines

Liangchao Li,Jiajun Wang,Lianfang Feng,Xueping Gu 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.11

Computational fluid dynamics (CFD) simulations were applied for evaluating the hydrodynamics characteristics in an uncovered unbaffled tank agitated by pitched blade turbines. A volume of fluid (VOF) method along with a Reynolds stress model (RSM) was used to capture the gas-liquid interface and the turbulence flow in the tank. The reliability and accuracy of the simulations are verified. The simulation results show that the vortex can be divided into central zone and peripheral zone, and flow field in the tank can be divided into forced vortex flow region and free vortex flow region. With the increase of impeller speed, the vortex becomes deeper, while the critical radius of the two zones keeps almost unchanged. The impeller clearance and the rotational direction have little effect on the vortex shape. The vortex becomes deeper with increasing of the impeller diameter or the blade angles at the same rotational speed. Power number is little influenced by the impeller speed, and decreases by about 30% when impeller diameter varies from 0.25T to 0.5T. When blade angle varies from 30o to 90o, power number increases by about 2.32-times. Power number in uncovered unbaffled tank is much smaller than that in baffled tank, but is very close to that in a covered unbaffled tank. The discrepancy of power number in uncovered unbaffled tank and that in covered unbaffled tank is less than 10%.

Facile Synthesis of Zn1-xCuxO Nanorods with a Very Broad Visible Band

Jianguo Lv,Changlong Liu,Wanbing Gong,Zhenfa Zi,Xiaoshuang Chen,Kai Huang,Feng Liu,Tao Wang,Gang He,Xueping Song,Zhaoqi Sun 대한금속·재료학회 2012 ELECTRONIC MATERIALS LETTERS Vol.8 No.5

Zn1-xCuxO nanorods with different Cu concentrations are prepared by a hydrothermal method. Bent and aggregated nanorods are obtained, which is attributed to centripetal surface tension of the evaporation and coagulation processes of the water film on the ZnO nanorods. The broad visible band consists of one violet, three blue,and one green emission. The violet emission is due to the transition of electrons from zinc interstitial (Zni)levels to the valance band. The three blue emissions may be attributed to the transition from extended Zni levels, which are slightly below the simple Zni level, to the valance band. The change of the green emission may be the result of competition between oxygen vacancies (VO) and zinc vacancies (VZn).

Precise visualization and ROS-dependent photodynamic therapy of colorectal cancer with a novel mitochondrial viscosity photosensitive fluorescent probe

Runsha Xiao,Fan Zheng,Kuo Kang,Lei Xiao,Anyao Bi,Yiting Chen,Qi Zhou,Xueping Feng,Zhikang Chen,Hao Yin,Wei Wang,Zihua Chen,Xiaomiao Cheng,Wenbin Zeng 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Background Colorectal cancer (CRC) is a prominent global cancer with high mortality rates among human beings. Efficient diagnosis and treatment have always been a challenge for CRC management. Fluorescence guided cancer therapy, which combines diagnosis with therapy into one platform, has brought a new chance for achieving precise cancer theranostics. Among this, photosensitizers, applied in photodynamic therapy (PDT), given the integration of real-time imaging capacity and efficacious treatment feasibility, show great potential to serve as remarkable tools. Although much effort has been put into constructing photosensitizers for locating and destroying CRC cells, it is still in high need to develop novel photosensitizers to attain specific detection and fulfil effective therapy. Methods Probe HTI was rational synthesized for the diagnosis and treatment of CRC. Spectrometric determination was carried out first, followed by the 1O2 generation ability test. Then, HTI was displayed in distinguishing CRC cells from normal cells Further, the PDT effect of the photosensitizer was studied in vitro. Additionally, HTI was used in CRC BALB/c nude mice model to validate its viscosity labelling and tumor suppression characteristics. Results We successfully fabricated a mitochondrial targeting probe, HTI, together with remarkable viscosity sensitivity, ultralow background interference, and excellent 1O2 generation capacity. HTI was favorably applied to the viscosity detection, displaying a 11-fold fluorescent intensity enhancement in solvents from 1.57 cp to 2043 cp. Then, it was demonstrated that HTI could distinguish CRC cells from normal cells upon the difference in mitochondrial viscosity. Moreover, HTI was qualified for producing 1O2 with high efficiency in cells, supported by the sparkling signals of DCFH after incubation with HTI under light irradiation. More importantly, the viscosity labelling and tumor suppression performance in CRC CDX model was determined, enriching the multifunctional validation of HTI in vivo. Conclusions In this study, HTI was demonstrated to show a sensitive response to mitochondrial viscosity and possess a high 1O2 generation capacity. Both in vitro cell imaging and in vivo tumor treatment trials proved that HTI was effectively served as a robust scaffold for tumor labeling and CRC cells clearance. This breakthrough discovery held immense potential for advancing the early diagnosis and management of CRC through PDT. By leveraging HTI’s properties, medical professionals could benefit from improved diagnostic accuracy and targeted treatment in CRC management, ultimately leading to enhanced patient outcomes.